The news of Colin Kaepernick's potential return has sent speculation about landing spots into overdrive.
But, taking a step back, how would we place such a comeback in a historical perspective, and how likely is Kaepernick to succeed on the field?
To be clear, debating what kind of performance we might expect from Kaepernick is in some ways beside the point. By the NFL's own admission he should have been in the league the past few years. Still only 32, Kaepernick is owed at least a full season on a roster, in my opinion, as part of any recompense related to restarting his career on the field.
It's probably not surprising that a return like the one Kaepernick now appears to be on the verge of making -- one where a star athlete comes back after missing multiple consecutive seasons or years -- is relatively rare in modern sports history.
Of course, seemingly an entire generation of pro athletes sacrificed multiple years to serve during World War II and the Korean War, and returned to the pro ranks afterwards. For baseball players alone, this is a list unto itself.
Military service would intervene in the careers of many fewer athletes after the second World War. Sadly, though, at least two of them didn't get a chance to resume their careers after their service. Bills rookie standout Bob Kalsu, an offensive lineman, died in Vietnam in 1970, and Arizona Cardinals safety Pat Tillman perished in Afghanistan in 2004.
The tragic conflict in southeast Asia proved to be at the center of arguably the most famous exit and comeback in sports history, and the one that is most analogous to Kaepernick's situation. It was of course a case of political persecution.
Others examples underscore incredible gains in science and medicine, while some marked stunning falls from grace -- and in some cases eventual redemption.
Here's a look at notable sports stars who resurrected their careers after long-term absences, and how they fared after they returned:
Like Kaepernick, Ali ran afoul of an establishment that had little appetite for his defiance.
The Greatest was heavyweight champion when his career was famously derailed by a draft evasion conviction, at age 25, in June 1967. He was subsequently stripped of his boxing titles and denied licenses to fight, and was sentenced to five years in prison but remained free while he appealed the case.
Ali refused to join the military amid the Vietnam war, on the grounds of conscientious objection. He had famously joined the Nation of Islam shortly after capturing the heavyweight title from Sonny Liston early in 1964, and said fighting in Vietnam was impermissible on religious grounds as well as for what he called the rank hypocrisy of a government that couldn't assure equality for the same black people it was asking to risk their lives abroad.
The war slogged on while Ali's case was tied up in court for several years. It became increasingly consuming and divisive in American society, particularly after the Tet Offensive in January 1968 marked the escalation of a bloody new phase of the war in that chaotic year.
Ali proved prescient about the folly of the war. He was allowed to return to boxing in October 1970, before his appeal was even settled. The case went all the way to the US Supreme Court, where his conviction was overturned in a unanimous decision in 1971.
He authored a thrilling second chapter of his career in the ring after his comeback, including his epic fights with Joe Frazier and the legendary 1974 Rumble in the Jungle against George Foreman, in which he reclaimed the heavyweight title.
Still, the ordeal cost Ali nearly four years in the prime of his career, from ages 25-28.
In retirement, Ali became an elder statesman of the civil rights movement and raised awareness for Parkinson's, the debilitating disease that broke down his body but not his spirit. Ali's embrace by an establishment that once despised him marked one of the great narrative arcs in sports history, and vindicated him as a visionary and humanitarian.
Will Kaepernick enjoy a similar ending?
Leave it to His Airness to come back so nice he had to do it twice.
Michael Jordan famously left basketball -- for a first time -- in 1993 to pursue a career in minor league baseball. The exact motive for the stunning move remains debated to this day, but it remains one of the most shocking and unlikely stories in sports history, one you probably wouldn't believe if you read it in a work of fiction.
Jordan walked away after completing the first of his three-peats with the Bulls in early summer 1993. He spent 1994 with the Birmingham Barons, the Double-A affiliate of the Chicago White Sox, and showed flashes of potential as a prospect, but he had trouble at the plate, racking up lots of strikeouts. He returned to the Bulls in spring of 1995 -- wearing No. 45 after deadpanning "I'm back" -- when the team was gearing up for its playoff run, nearly two years after he last suited up for Chicago.
Jordan was magnetic to watch but he showed some rust in his return, and the Bulls were knocked out of the playoffs in the second round by Shaquille O'Neal and the Orlando Magic. But Jordan of course returned to form, capturing the first title in his second three-peat the following season. He retired in 1998 and remained on the sidelines for three seasons this time, only to return for a second time with the Washintgton Wizards at age 38 in 2001-02. Jordan was a lesser version of himself in the second comeback, though he still notched over 20 points per game.
Arguably the most celebrated heavyweight since Ali himself, Mike Tyson took the boxing world by storm in the mid- and late 1980s, winning his first 19 career bouts by knockout, and later becoming the youngest heavyweight champion in history at just 20 years of age in November 1986.
Tyson's dominance, swagger and fearlessness made him a cultural icon as well. He of course lent his name to the seminal video game Mike Tyson's Punch-Out for Nintendo, which was a huge seller in the US.
Tyson's first loss as a professional didn't come until February 1990, when he was stunningly upset by Buster Douglas in Tokyo, Japan. But afterwards, he appeared to be getting back on track, reeling off several wins in a row, including two over Donovan Ruddock, and there was a potential blockbuster fight against Evander Holyfield on the horizon.
Except the Tyson-Holyfield fight would have to wait about half a decade.
Outside the ring, reports had surfaced for years about Tyson's violent and volatile behavior. Actor Robin Givens, his first wife, famously accused him of physical and emotional abuse. Later, in 1991, Tyson was charged with raping an 18-year-old Miss Black America contestant. The sensational high-profile case was one of the first of its kind in the 24-hour cable news cycle, with international media swarming to Indianapolis, IN to cover it.
In 1992 Tyson was found guilty of rape and sentenced to six years in prison. He served three years before his release in 1995, returning to the ring that year. Three victories, including two title fights, set up the years-in-the-making matches against Evander Holyfield, billed as "Finally." Tyson lost both, including the rematch which was marred by his disqualification for biting Holyfield's ear.
Holyfield thoroughly outboxed Tyson both times, effectively marking the end of Tyson's career as a respected and feared fighter. Tyson has struggled with his fame and infamy ever since, battling substance abuse and reportedly dealing with financial woes -- while also remaining on the periphery of popular culture, for example appearing in movies, and is due to be portrayed by Jamie Foxx in an upcoming biopic. It is also worth noting that by today's mores, it seems unlikely Tyson would have been back in a ring three years after a rape conviction.
Like Tyson before him, Michael Vick's career was stunningly upended by criminal charges that led to an eventual conviction and prison time.
Vick was a bona fide NFL superstar with the Atlanta Falcons when he was hit with federal and state charges in relation to a dogfighting ring. Vick pled guilty to federal racketeering charges, as well as dogfighting in his home state of Virginia. He served 21 months in federal prison in Kansas, costing him the 2007 and 2008 seasons.
The incident also cost Vick millions in endorsement deals, but the Falcons didn't actually cut him until shortly before he was released from prison, fueling speculation about whether he would return to the NFL at all, and if so where he might end up.
The Eagles took the plunge weeks before the 2009 season, to some criticism. But Vick had paid his debt to society, and was able to resume his career with relatively little protest or opposition. He played little in '09 but came back with a vengeance in 2010 when circumstances pushed him back into the starting lineup. Donovan McNabb was gone from Philly, and starter Kevin Kolb suffered a concussion, opening the door for Vick.
Vick enjoyed arguably his best season as a pro in 2010, three full years after he lost his job as Falcons starter. He earned a Pro Bowl nod for his efforts in the Eagles' explosive offense, authoring a new chapter to his career. He remained contrite about his role in torturing animals while finishing out his career with the Jets and Steelers, and maintained that he was a changed person throughout.
Mario Lemieux stunned the world when he retired from the NHL while still very much in his prime at the age of 31 in 1997. Several news articles from the time declared Lemieux was the first star professional athlete to walk away from sports altogether during his peak since Jim Brown.
The Magnificent One to Wayne Gretzky's Great One, Lemieux had battled back ailments and Hodgkin's lymphoma for several years, and apparently felt his body could no longer hold up. Even in what Lemieux deemed to be a disappointing 1996-97 campaign, he managed to lead the league in points, with 122.
The Penguins quickly fell apart without the player who was not only their best, but also the face of Pittsburgh hockey and indeed one of the faces of the league. The franchise lapsed into bankruptcy, and the team was rumored to be facing a quick sale and potential relocation to another city.
Enter Lemieux, who just so happened to be one of the franchise's largest creditors, since it owed him millions in deferred salary. He purchased the team and later returned to the ice at age 35, after missing three full seasons, reportedly becoming the first owner-player in modern sports history in the process. Upon his return, Super Mario finished second in MVP voting in 2000-01, and notched two more All-Star nods before retiring for good in 2006.
Bernard King's tale of determination to come back against major odds was a huge inspiration and one of the first of its kind.
King was leading the NBA in scoring at just shy of 33 points through the first 55 games of the 1984-85 season -- when he blew out his knee in horrific fashion. King suffered a torn ACL and several fractures, and at a time when reconstructive orthopedic surgery was relatively rare for pro athletes, it appeared his career was in serious jeopardy.
King missed the balance of the '84 season and all of 1985-86, before finally returning for six games at the tail end of the 1986-87 campaign. He looked good in the very small sample, but understandably the Knicks were not convinced he'd be back to the player he once was ,and allowed him to walk in free agency.
King signed on with the Bullets and steadily recaptured his pre-injury form. In 1991 he earned his fourth All-Star nod and first since his injury, which he later called the crowning achievement of his career. Sometimes being one of the first to do something is about being in the right place and right time, but it seems few could have matched the determination King is said to have drawn on to get him through what was then a grueling and uncharted rehab process.
Like King before him, Garrison Hearst similarly came back from an injury situation that for all intents and purposes should have ended his career.
Hearst had quietly rounded into a borderline star running back, with three 1,000-yard rushing seasons under his belt and a pass-catching skill set that made him versatile out of the backfield. His magnum opus was his standout 1998 campaign at age 27, in which he eclipsed 2,000 combined yards -- 5.1 per carry and a whopping 13.7 per catch.
Cruelly though, Hearst broke his ankle in the playoffs that year. Worse, what he was told would be a relatively routine recovery went haywire, and he developed avuncular necrosis, the condition that ended Bo Jackson's football career. He was told he might never walk without a limp again, let alone run at with the kind of strength and power required of an NFL running back.
Hearst defied the odds, though, subjecting his mended leg to the brutal poundings of the league once again upon his return in 2001, after a full two seasons on the sidelines. Amazingly, he eclipsed 1,200 yards rushing in that comeback season, earning him a Pro Bowl nod. He played three more seasons before retiring in 2004 at age 33.
Monica Seles had emerged as arguably the best in the crowded ranks of womens tennis in the early 1990s. By 1993, she'd claimed eight grand slam titles in nine finals appearances, including a 3-1 record against her chief rival, Steffi Graf. Seles was an all-time great at that time, and she might have been destined for even more.
Sadly, Seles was stabbed in the back during a match in April 1993, reportedly by a deranged fan of Graf's, in Hamburg, Germany. The injuries weren't life- or career-threatening, but understandably she later admitted that she struggled with the emotional trauma for a long time after.
Seles and her patented two-hand lefty forehand returned to the court in August 1995 -- and she quickly captured her ninth grand slam title only a few months later, at the 1996 Australian Open. It seemed her career dominance would resume unabated, but it proved to be her final victory in a slam. Still, Seles played top-level tennis for another seven years after her courageous comeback, until she retired in 2002.
David Robinson had all the makings of a ready-made NBA superstar when the San Antonio Spurs drafted him with the first overall pick in 1987. The only problem was he couldn't yet play.
Robinson dominated the college ranks at the US Naval Academy and appeared ready to do so at the next level, but he owed Uncle Sam the customary two years of service time upon his graduation, a minor obstacle if you're looking to play in the NBA. Robinson had reportedly considered leaving the academy early to avoid the potentially sticky dilemma, but after sticking it out through graduation, things came to a head.
Robinson put basketball on hold and fulfilled his commitment at Naval Submarine Base Kings Bay in Georgia. In 1989 he finally joined the Spurs -- after agreeing not to re-enter the draft in exchange for a specially constructed contract that paid him among the highest on the team.
How would Robinson actually play after the layoff? He proved worthy of the investment, leading the 1989-90 Spurs to one of the biggest one-year turnarounds in NBA history, and enjoying a stellar career that included two titles, an MVP, and enshrinement in the Hall of Fame.