Four Days and Counting... continues its day-by-day preview of Saturday's Indiana-Michigan game with four key matchups to keep an eye on at the Big House in Ann Arbor.

IU C Chris Mangiero vs. MICH NG Gabe Watson-Michigan hasn't been as formidable against the run as it usually is, giving up 146.2 yards/game and 4.0 yards per carry. Indiana continues to try to get some sort of consistency out of its running attack to provide balance with the pass, and that will be the case again this weekend.

Indiana generally likes to run between the tackles, so it will be up to Mangiero to keep this 6-4, 331-pound senior from getting into the backfield and disrupting the ground attack before it can even get started. Watson is athletic for his size, and he's a load to move as well. This will certainly be one of the season's biggest challenges for Mangiero, a three-year starter up front for the Hoosiers.

Watson has been playing some of his best football as of late, recording 19 of his 33 tackles in his last four games. He was particularly effective against Northwestern, when he recorded three tackles and forced three holding calls as well. He's tallied 5 ½ tackles for loss and three sacks as well. Indiana can't afford to have negative plays in the running game if it hopes to spring an upset Saturday. Second and third-and-longs will allow the likes of Lamarr Woodley to get after Blake Powers, which could result in a long day for the Hoosier quarterback and the IU team as well.

IU CB Tracy Porter vs. MICH WR Jason Avant-The Hoosiers' top coverman will have his hands full with Avant, who's one of the Big Ten's most productive wide receivers with 65 catches, 834 yards and six touchdowns. No other player on the Michigan roster has more than 17 catches this season.

Avant is a big, physical wideout at 6-1 and 210 pounds, someone who will position himself well and try to keep Porter from getting his hands in on balls. Porter, who leads the Hoosiers with three interceptions, has been susceptible on slants, particularly around the goal line. That's a route that Avant will likely run on numerous occasions, using his size to shield Porter from the ball, and then trying to use his strength to break a tackle and turn it into a big play.

Porter has big-play capabilities, and he'll need to play his best game of the year to match up with one of the Big Ten's best wideouts. But if he can manage to take away Chad Henne's No. 1 target or force him to look elsewhere, it will give the Hoosiers a fighting chance to spring an improbable upset in Ann Arbor. Leslie Majors will have his hands full with speedsters Steve Breaston and/or Mario Manningham on the opposite side, but Indiana needs to take away some of the intermediate routes on 3rd downs and make Henne beat them downfield.

Blake Powers vs. Michigan Defense in the Red Zone-While a couple of big-plays would be huge for Indiana, Indiana also needs to capitalize on its trips inside the Michigan 20 with touchdowns, not field goal attempts. Michigan's defense has been unusually generous this season, allowing teams to average 401 yards/game. But they've been stout inside the 20. Opponents have ventured inside the Michigan 20-yard line 30 times this season and come away with only 13 touchdowns.

Red zone inefficiency kept the Hoosiers from being in the Michigan State game a couple of weeks ago. Not only did Blake Powers throw an interception in the end zone and another in the red zone, but Indiana had two other turnovers inside the Michigan State 25 on their first two drives of the second half. Indiana actually marched the ball inside Michigan State territory on six of its first eight drives in East Lansing, yet came away with just seven points and three turnovers.

The Hoosiers can't do that again this weekend if they hope to avoid a similar result to the one that happened two weeks ago. It will be on Powers to be productive in the red zone, and to avoid the same costly turnovers that squandered any sort of chance for an upset in East Lansing.

Marcus Thigpen vs. Michigan Defense-The Indiana coaching staff is obviously trying to get this redshirt freshman more involved. Thigpen caught a season-high five passes for 86 yards against Minnesota, and also ran a reverse and took a direct snap as well to try to make something happen in the running game.

With James Hardy's status unclear for this weekend's game, Indiana needs someone in the wide receiving corps to make a big-play or two to give Indiana a chance. While Hardy is clearly the No. 1 threat deep downfield, Thigpen is someone who can make plays in the open field. Indiana is going to need a couple of big hitters to knock off a team it hasn't beaten on the road in 38 years, and Thigpen is capable of doing just that. It hasn't happened since he broke free for a 50-yard plus touchdown in the season-opener against Central Michigan, but Thigpen is more than capable.

Thigpen's contributions are even more important with the uncertainty of Hardy's availability and the fact that the team's second-leading receiver, James Bailey, has been kicked off the team for the time being. Thigpen will be on the field on just about every offensive snap, and he will also undoubtedly have a little extra adrenaline for this contest. As a Detroit native who wasn't recruited by the Wolverines, Thigpen would like nothing more than to prove that Lloyd Carr made a mistake in overlooking him.

What's coming up:
On Monday – Five Numbers to Note
On Tuesday - Four Key Matchups
On Wednesday – Three Big Concerns
On Thursday – Two Things IU Must Do to Win
On Friday – One Bold Prediction
On Saturday – Hoosier Gameday Top Stories