Kizer struggled last week, completing just 12 of his 20 pass attempts for 114 yards, no touchdowns and two interceptions.
After replacing him in the second half, Kessler was 10-of-19 for 121 yards, no touchdowns and one pick.
Kizer has gone through growing pains during his rookie season with a 0-6 record as a starter. He has completed just 52.0 percent of his passes for three touchdowns and an NFL-worst 11 interceptions.
The second-round pick out of Notre Dame has also rushed for 126 yards and two touchdowns.
Kessler was a third-round pick in the 2016 NFL draft out of USC, and he was impressive at times in eight starts last season as a rookie.
Although he went 0-8, Kessler threw for 1,380 yards, six touchdowns and two interceptions, while completing 65.6 percent of his passes.
Kizer will have a major challenge on his hands in Week 8 against a Vikings defense that ranks fourth in total yards allowed per game (283), fifth in points allowed per game (17.0) and eighth in interceptions (7).