Jacoby Brissett, recently acquired in a trade with the New England Patriots, replaced Tolzien, who was 9-of-18 for 128 yards and two interceptions, both of which returned for a touchdown.
Bleacher Report showed just how bad the day was going for Tolzien, who departed with the Colts losing 37-3 to a team that went 4-12 last season:
Things went much better for Brissett as the quarterback threw a 50-yard pass to Donte Moncrief on his first pass of the game. The Colts scored their first touchdown of the day two plays later.
Tolzien had only made three career starts entering the day in five years in the NFL, leading his teams to an 0-2-1 record in this stretch. He had two touchdowns and seven interceptions.
Meanwhile, Brissett represents a more high-upside player as a third-round pick in the 2016 draft. He appeared in three games as a rookie last season, posting an 83.9 quarterback rating despite not throwing a single touchdown pass.
The Colts traded away receiver Phillip Dorsett to bring in the young player, so it makes sense for them to give him a chance even if he is unfamiliar with the system.
Considering Luck could still be "several weeks" away from returning, per Jason La Canfora of CBS Sports, Brissett might have to take on a bigger role going forward.