What do Trace McSorley, Alex Hornibrook and Jeff George Jr. all have in common? They are the only three quarterbacks to survive a full four quarters against Michigan’s defense this season.

Playing quarterback against the Wolverines in 2016 can be bad for your passer rating and bad for your health. The physical Michigan defense, which leads the nation in a litany of stats, including points allowed per game and passing yards allowed per game, has worn down players at many positions. Those stats are helped by the fact that they’ve played more than half their games during a 9-0 start against a backup quarterback in the fourth quarter.

“We just say when your number is called, get home,” linebacker Jabrill Peppers said. “We don’t ever want to intentionally hurt anybody, but we want you to feel us when we hit you.”

Peppers’ sack of Hawaii’s Ikaika Woolsey at the end of the first half in Michigan’s opener ended his day. The following week, UCF’s Justin Holman injured his leg during a long run in the second quarter. Rutgers’ Chris Laviano didn’t even make it out of the first quarter before he ended his day with a 1.2 QBR score, completing one of his eight pass attempts.

This past weekend, Maryland senior Perry Hills was a perfect 4-for-4 when he left the game in the second quarter with a shoulder injury. Michigan defensive lineman Chase Winovich slipped through the middle of an offensive line that was sprinting to the sideline to set up a wide receiver screen pass and launched himself at Hills -- the Big Ten’s leader in passing efficiency at that point -- a split second after the quarterback released the ball.

He did not return to the game and his two replacements combined to complete 50 percent of their passes and throw two interceptions.

“There have been several situations where a lot of these teams run the bubble screens and don’t protect,” Michigan coach Jim Harbaugh said. “Our guys are blitzing. That puts the quarterback in harm’s way. Our guys have been good in their blitz tempo and their relentlessness up front. [The pass rush] has been a real positive for us. That’s really the backbone of our team, that defensive line.”

Maryland's Perry Hills is the latest quarterback to feel the wrath of the Michigan defense. Gregory Shamus/Getty Images

Winovich said he hoped Hills would have a speedy recovery -- he is day-to-day and might return in time for Saturday's game against No. 5 Ohio State. Winovich also said that he and his teammates have noticed the trend of seeing a new face at quarterback by the end of most games.

“We’re not targeting players, but it is a notable thing. I think we’re up to eight quarterbacks that haven’t finished the game,” he said, giving a count that includes both Colorado and Michigan State playing three quarterbacks against the Wolverines. “That is an interesting point that kind of reflects the style of play we have. … Nobody is safe in this game, especially when you’re playing quarterback against us. We’re coming.”

The combination of a deep, veteran defensive line and the many blitz packages employed by defensive coordinator Don Brown helped Michigan rack up 30 sacks in its first nine games. Only seven teams in the country have more. They also chip away at quarterbacks with hurries and hits that are near-misses for sacks. No quarterback felt that more than Colorado’ s Sefo Liufau.

Liufau threw for 246 yards and three touchdowns during the best first half any team has had against the Wolverines this season. He also paid a price for it. He was bruised and battered by halftime – even taking an unintentional hit while talking to an athletic trainer on the sideline. He injured his ankle in the third quarter, and despite toughing it out for long enough to throw his final touchdown pass a couple plays later, it eventually ended his day.

The final touchdown pass for the Buffs made them the only team to take a lead against Michigan in the second half of a game this season. Liufau’s replacement, Steven Montez, didn’t complete a pass and the Wolverines pulled away for a 45-28 victory.

“We try to wear everyone down,” said Ryan Glasgow, who sacked Liufau on his final play at the Big House. “… With quarterbacks, we go out there with no ill will or malicious intent. We’re taught to run through hits. We don’t want to be missing tackles. We have no malicious intent, but we’re going to play the game of football. It’s a physical game.”