Coan has made 18 career starts and started all 14 games for Wisconsin last year as the Badgers went 10-4 with losses in the Big Ten championship game and Rose Bowl.
He had a school-record 236 completions for 2,727 yards with 18 touchdowns and five interceptions last season. He completed 69.6% of his passes and also had four touchdown runs.
Mertz was rated as the nation’s No. 3 pro-style quarterback and No. 65 overall prospect in his high school class according to composite rankings of recruiting sites compiled by 247Sports. He appeared in blowout victories over Central Michigan and Kent State while redshirting last season and went 9 of 10 for 73 yards.
“He’s put a lot of time in, and I think he is progressing certainly,” Chryst said.
The Badgers also return junior Danny Vanden Boom and sophomore Chase Wolf, who appeared in three games last year and completed his only pass for 2 yards. Vanden Boom didn’t play last season but made three appearances in 2018 and completed his only pass for a 3-yard touchdown.
The injury to Coan provides one more hurdle for an offense that already was replacing two-time Doak Walker Award-winning running back Jonathan Taylor, wide receiver Quintez Cephus and All-America center Tyler Biadasz on offense.
“We’ve got good guys, good players,” Chryst said. “Maybe they don’t have experience, but it doesn’t mean they won’t be real capable of being good. That’s one of the neat things about college football.”