In a perfect world, the true freshmen on Michigan football team's defensive corps would develop over time and take baby steps before being thrust into action.

That hasn't been the case.

In what has been a tumultuous six-week crash course, seven true freshmen have been forced to play and pay for their mistakes as they learn.

"Most coaches will tell you that true freshmen who play are either so talented that you have to get them on the field some way or they are talented enough that you've got to play them because of your numbers and depth is what it is," Michigan coach Rich Rodriguez said this week. "That's where we're at.

Michigan freshman cornerback Terrence Talbott looks to stop Michigan State wide receiver Keshawn Martin during the second half at Michigan Stadium on Saturday. Michigan lost to Michigan State, 34-17. Melanie Maxwell I AnnArbor.com

"It bodes well because they're getting experience, but you would rather not have to have them cut their teeth this early."

Four of the seven freshmen have been asked to fill in the gaps of a secondary that has allowed an average of 304 passing yards heading into Saturday's homecoming date with No. 15 Iowa (3:36 p.m., ABC).

Michigan's secondary was thin before senior cornerback Troy Woolfolk was lost for the season began. Suddenly, freshmen cornerbacks and safeties Terrence Talbott, Cullen Christian, Marvin Robinson and Ray Vinopal were on the field.

Defensive end Jibreel Black, hybrid safety Carvin Johnson and cornerback Courtney Avery also have seen playing time. Talbott has eight tackles and broken up a pass after six games. Avery has six tackles and broken up two passes.

Although Michigan's veterans know they have to be patient, they insist the time will come when the improvements they see in practice carry over to games.

"There's going to be a point when they turn over a new leaf and all of a sudden they get it," senior defensive end Ryan Van Bergen said. "That's how football is. Sometimes it clicks and sometimes, it doesn't. Once it clicks once for you, you'll know how to do it over and over and over again.

"Once we get that to happen for a couple different guys, things will definitely start rolling our way."

During last week's 34-17 loss to Michigan State, a 41-yard Kirk Cousins' touchdown pass to Mark Dell helped turn the tide for good. Christian, who was inserted after starting right cornerback James Rogers left the game with cramps, got turned around in coverage.

Dell sprinted past him and made the catch, extending the Spartans' lead to two touchdowns.

Rodriguez said while some of his team's defensive struggles can be corrected immediately, others will take time. Some improvement will come as freshmen continue to pick up on a scheme that Rodriguez said he has scaled back.

At some point, though, Van Bergen said his inexperienced teammates have to make things happen.

"When it comes down to it, they're either going to make the play or they're not," Van Bergen said. "I think those guys can make the plays and I think some of them are starting to develop the attitude that young is just an excuse.

"They've been through six games now and to say they're inexperienced, they're more experienced than most (true freshmen), and so they need to get together and make the decision that they're going to play and that they're going to play well."

Senior defensive tackle Greg Banks believes Michigan's veterans have to cover some of the slack. Most of the Wolverines' most experienced defensive players reside either on the line or at linebacker - positions Banks said can help ease the transition for the freshmen.

Michigan's defense sacked Cousins twice in last week's loss, but also pressured the quarterback more than it had in previous weeks.

"Even if we had lock-down coverage from the (defensive backs) putting pressure on is just something that dominating (defensive) lines do," Banks said. "That's what we're trying to be. Regardless of who is standing behind us, we want them to look at us and say, 'You guys are the workhorses and you're stopping them, you're getting sacks and you're putting pressure on.'

"So we take that on ourselves."

Rodriguez said it's up to the freshmen to learn from their mistakes.

"They've done some good things," Rodriguez said. "That's the thing. I think they're growing up even though there are some growing pains with that. I think it's going to be exciting to see what they're going to keep doing. But to play this many true defense on defense at this level? It doesn't happen very often."

Jeff Arnold covers sports for AnnArbor.com and can be reached at (734) 623-2554 or by e-mail at jeffarnold@annarbor.com. Follow him on Twitter @jeffreyparnold.