The Montreal Alouettes announced that Manziel will be their starter when they host the Hamilton Tiger-Cats.
The 2012 Heisman Trophy winner began the season with Hamilton and was dealt to Montreal on July 22 in a five-player deal that also included two first-round draft picks.
"I feel fortunate enough this week to be going against a team, a defense that I've seen more than any other defense since I've been in the CFL," Manziel said Tuesday. "I feel like I really know this personnel very well, I feel like I know this team in and out because I was a part of it.
"It's definitely going to be a little weird playing against those guys, but at the end of the day it's business and I'm in a new home. It will be good to see some familiar faces this week, but also a challenge and a very good defense."
Montreal acquired Manziel and offensive linemen Tony Washington and Landon Rice for receiver Chris Williams, defensive lineman Jamaal Westerman and 2021-22 first-round draft picks. The move reunited Manziel with Alouetes coach Mike Sherman, who recruited Manziel to Texas A&M.
Manziel dressed for Montreal's 44-23 loss last week to Edmonton but didn't play. Vernon Adams Jr. completed 15 of 28 passes for 217 yards and an interception while rushing for 72 yards and a TD on eight carries.
Adams, a former teammate of Manziel's in Hamilton, wasn't surprised by the move.
"We all knew he wasn't coming just to sit," Adams said. "We helped him learn the offense as quick as possible, he's still learning.
"Now, I'm going to be here for him, back him up. Whatever he needs help with, I'm here for him."
Manziel made headlines in May when he signed a two-year deal with Hamilton. He played in both of the Tiger-Cats' exhibition games — completing 21 of 31 passes for 168 yards and a TD while rushing six times for 19 yards — but remained on the sidelines as Jeremiah Masoli's backup once the regular season began.
"We obviously traded for John for a specific reason," Sherman said. "I think we have two very good quarterbacks but we're going to give the nod to John for this ballgame. I'm very impressed by the knowledge that he does have at this point."
The contest is between two struggling teams as Hamilton (2-4) and Montreal (1-5) have each lost three straight games.
The 6-foot, 210-pound Manziel was taken in the first round, No. 22 overall, by the Cleveland Browns in the 2014 NFL draft but was released in March 2016 after posting a 2-6 record over two tumultuous campaigns on and off the field.
Manziel, 25, appeared in 14 games overall, throwing for 1,675 yards and seven TD passes.
The game Friday will be Manziel's first regular-season start since Dec. 27, 2015, when he completed 13-of-32 passes for 136 yards and an interception while running for 108 yards in Cleveland's 17-13 road loss to the Kansas City Chiefs.
"I felt like the thing I've been missing ... is reps," Manziel said. "I don't think there's anything to be nervous about. I feel like as the game comes around this week I'm going to know what I'm doing on each and every play and know what my job is.
"I think there's going to be some times where we're not going to win every single play as the game goes along. There's going to be some mistakes made, that's just the facts of this. I think I'll come out and do some things well, and I'm sure I'll have some things I want back. That's just the way that football is anytime and anywhere I've started."