[2][3] He made he team as the third-string quarterback and dressed for all 18 regular season games where played sparingly, as he completed two passes from three attempts for 17 yards.
[4] McGuire signed a one-year contract extension with the Blue Bombers on December 31, 2020.
[5] With the departure of the team's previous backup quarterback, Chris Streveler, to the National Football League, McGuire won the back-up position behind starting quarterback, Zach Collaros.
McGuire was used regularly on the short yardage team and scored his first two career touchdowns on quarterback sneak plays on September 5, 2021, in the Labour Day Classic against the Saskatchewan Roughriders.
[7] McGuire completed 11 of 26 passes for 149 yards, a touchdown and four interceptions in his first CFL start as the Bombers were defeated 28–14 by the Alouettes.