Iowa quarterback Spencer Petras warms up before a game against Penn State on Oct. 9 in Iowa City, Iowa. (AP file photo)

IOWA CITY, Iowa — Spencer Petras will be the starting quarterback when No. 15 Iowa plays second-ranked Michigan in the Big Ten championship game on Saturday night.

Petras was listed first on the depth chart released at the start of the week, and coach Kirk Ferentz made it official Tuesday.

Petras started every game last year and the first nine games this season. He missed two full games with an injured right (throwing) shoulder before replacing Alex Padilla after halftime of last week’s 28-21 win at Nebraska.

“The way I see it, I got hurt, Alex stepped in and did a really good job,” Petras said. “I just think at this time of year, it’s not as much of a competition. That takes place in fall camp. It’s more who can help the team win the best that week. When I was hurt, that was certainly Alex. It seems right now that it’s me.”

Ferentz said it was a “gut feeling” that prompted him to put Petras in the game with Iowa trailing the Cornhuskers 14-6 at half last Friday.

“I thought he did a good job,” Ferentz said. “And he’s done a lot of good things over two years. We haven’t forgotten about that at all.”

Petras was 7 of 13 for 102 yards, had the game-winning 2-yard touchdown dive in the fourth quarter and had a critical third-down completion for a first down on the previous possession when Iowa tied the game on a field goal.

Petras was 6-2 as the starter last season, and he won his first six starts this season. But Petras hurt his shoulder in the 27-7 loss at Wisconsin on Oct. 30 and struggled the first three series at Northwestern the following week. Padilla replaced him and led the Hawkeyes to a 17-12 win, and he started in wins over Minnesota and Illinois.

“I think it’s similar with the confidence they both play with,” center Tyler Linderbaum said. “Maybe their voices are different, but that’s about it.”

Petras has completed 137 of 236 passes for 1,532 yards this season, with nine touchdowns against six interceptions. Padilla has completed 45 of 97 for 598 yards, with two touchdowns and one interception.

Petras said he’s “100 percent” healthy.

“It just takes me a little while longer to get warmed up,” he said.