It’s Week 9 in the Big Ten, and we’ve reached a critical juncture for many teams, especially several in the Big Ten West, where three of the four one-loss teams in that division are mild underdogs this weekend and looking to steal a victory.

With Ohio State and Michigan both off this week, the focus is clearly on that Big Ten West race this weekend.

Here are five players — some of whom we know very little about — with a lot to prove this weekend:

Jack Coan, Wisconsin quarterback

Late in the week, Wisconsin quarterback Alex Hornibrook is still going through concussion protocol, so it looks backup Jack Coan might very well get the first start of his career in a huge Big Ten West game at Northwestern. Coan hasn’t played at all this year because the Badgers were hoping to redshirt him. New  NCAA rules allow him to play up to four games and still maintain the year of eligibility, and there are only five games left. But something will have to give Saturday. This is a big game and we have no idea what to expect from Coan. “Jack has done a great job in the spring and summer and in fall camp,” Wisconsin coach Paul Chryst said. “Jack’s taken a ton of reps with our ones and our twos, because we always knew that if something were to happen, he would be the next one to go in.” Next man up, indeed.

Rocky Lombardi, Michigan State quarterback

The same injury bug is biting Michigan State, because it looks like quarterback Brian Lewerke and his injured right shoulder won’t be ready to go Saturday when the Spartans host Purdue. Rocky Lombardi, the backup, has virtually no experience himself.  It’s a tough position to be in, because all of his top receivers are injured and the offense line has been a banged-up mix-and-match group all season. The freshman from Clive, Iowa, threw his first-ever passes last week, going 1-for-2 for 9 yards late in the fourth quarter of the 21-7 loss to Michigan a week ago. He’s probably going to be thrown into the fire Saturday, and he’ll have to respond.

Miles Sanders, Penn State running back

Iowa’s defense is terrific, so if Penn State is going to snap its two-game home losing streak, running back Miles Sanders is going to have to have a big game. Iowa is No. 3 in the country in total yards allowed and No. 3 in rushing yards allowed. Sanders had 162 yards against Michigan State’s vaunted defense two weeks ago, but 78 yards of that came on one rush. Iowa shut out Maryland last week and is one play away from having two other shutouts earlier this year. It’s on Sanders to break a big play or two this game as well.

Purdue quarterback David Blough

Purdue is coming off its biggest win in years, upsetting No. 2 Ohio State last weekend in West Lafayette. Now it’s time to validate that win and keep the Boilermakers’ four-game winning streak going by beating a banged-up and damaged Michigan State team in East Lansing. The Spartans will still smack you in the mouth, but this is a game the Boilers need to steal on the road, and Blough is a big part of that. He’s been red-hot lately — 13 touchdown passes in the past five games against only  two interceptions — and he needs to keep that up Saturday against Michigan State.

Isaiah Bowser, Northwestern running back

Freshman running back Isaiah Bowser burst onto the scene last week in his first taste of extended action, and rushed for 108 yards on 24 carries in Northwestern’s win over Rutgers. He needs to do it again this week when the Wildcats host Wisconsin. The Badgers are banged up and a bit of a mess right now, and if the Wildcats can run the ball successfully, they can pull of an important upset here. It’s on Bowser’s shoulders now.