Kelly, who is entering his second season as the OC but his first calling plays, told media members Wednesday that the learning process last season helped prepare him for play calling.
His challenge will be taking those lessons and applying them so the Texans offense can improve to better than average.
One issue for the offense was the tendency to overly rely on DeAndre Hopkins, who was traded this offseason to the Arizona Cardinals.
It's hard to imagine the Texans being better without an All-Pro wide receiver, especially having not replaced him with another one.
But the Texans signed veteran slot receiver Randall Cobb, traded for deep threat Brandin Cooks and brought in running back David Johnson from the Hopkins trade.
Johnson is a known threat in the passing game.
The Texans want to spread the ball around and run better routes.
When Kelly was asked how the offense would look in 2020, and what it's like replacing a player like Hopkins, the coach had this to say:
"I think any time you take the field with multiple weapons, multiple guys who can hurt a defense at a variety of different levels -- not just necessarily deep, short or intermediate -- but be able to threaten every aspect of the field is a good thing. So as far as being able to attack the defenses and really as each opponent presents its own issue, being able to take advantage of different matchups throughout the entire field and not necessarily one player, it's an encouraging thing."
With Fuller missing five regular season games and Stills missing three games, the Texans struggled to locate receivers not named Hopkins.
With more weapons and another year under Deshaun Watson's belt, it's now Kelly's job to call the plays that will maximize what the Texans have.
This is the first season since O'Brien took over the team in 2014 they return all five starters on the offensive line.
"Again, we've got a great quarterback, a guy who's going to be able to distribute the ball and again get the ball to the guys that are winning," Kelly said. "And we've got guys who have won consistently for a long time scattered throughout that room. You look at Brandin (Cooks), you look at Randall (Cobb), you look at Will (Fuller V) and Kenny (Stills) obviously with the production they had last year, Keke (Coutee) and DeAndre Carter, Steven Mitchell (Jr.) made some big plays.