IowaâÄôs run at perfection will have to continue without a key cog in its offense. Redshirt freshman running back Adam Robinson will likely miss the remainder of the regular season with a high left ankle sprain, Iowa head coach Kirk Ferentz announced Tuesday during his weekly teleconference. He sustained the injury during the HawkeyesâÄô last-second 15-13 victory over Michigan State on Saturday. âÄúThereâÄôs a chance we could get him back at the end, but a running back with a bad ankle âÄî itâÄôs not a good thing,âÄù Ferentz said. âÄúThereâÄôs not much you can do.âÄù The Hawkeyes are 8-0 for the first time in school history. TheyâÄôre No. 4 in the Bowl Championship Series rankings, but little has come easy in 2009. Iowa needed two blocked field goals in the final seven seconds to beat Northern Iowa 17-16 in its season opener. Most recently, quarterback Ricky Stanzi found Marvin McNutt as time expired for a 7-yard touchdown to vault the Hawkeyes past Michigan State and keep the dream of a perfect season intact. That win came with a price, however, and now Iowa (8-0 overall, 4-0 Big Ten) goes forward without its leading rusher. Freshman Brandon Wegher will make his first career start Saturday at home against Indiana. Ferentz said heâÄôd love a blowout win instead of the nail-biters to which his team has become accustomed. Half of IowaâÄôs games have been decided by three points or less. A blowout seems much more possible at Kinnick Stadium against the Hoosiers (4-4, 1-3) as opposed to its past two games on the road against Wisconsin and Michigan State. Indiana squandered a 28-17 halftime lead a week ago at Northwestern and lost 29-28 on a late field goal. Its lone conference win remains a 27-14 victory over reeling Illinois. Purdue at Wisconsin After shocking then-No. 7 Ohio State 26-18 on Oct. 17, Purdue took its turn running over the hapless Illini and enters this weekendâÄôs game against Wisconsin on a two-game win streak after starting the season 1-5. The Badgers, meanwhile, coming off their bye week, dropped back-to-back games against then-No. 9 Ohio State and Iowa prior to their week off, despite opening the season with five straight wins . Few people would have expected Wisconsin and the Boilermakers to have matching 2-2 Big Ten records considering their vastly different starts. The game kicks off at 11 a.m. Saturday. Michigan at Illinois Illini head coach Ron Zook received a vote of confidence from his athletics director Ron Guenther during halftime of IllinoisâÄô 24-14 loss to Purdue last weekend; itâÄôs perhaps the only good news heâÄôs been given all season. Illinois (1-6, 0-5) has lost seven straight in the Big Ten dating to last season, and host a Michigan team Saturday fresh off of a 35-10 loss at the hands of Penn State. The Wolverines (5-3, 1-3) boast the best scoring offense in the conference (33.9 ppg); the Illini have the worst (16.1) and the worst scoring defense, as well (27.7 allowed). Those numbers donâÄôt bode well for an already demoralized Illinois team. No. 12 Penn State at Northwestern After a dramatic one-point win over Indiana, Northwestern (5-3, 2-2) sits just one victory shy of bowl eligibility. The Nittany Lions knocked off Michigan at the Big House last weekend behind a 16-for-27, 230 yard and four touchdown passing performance from senior quarterback Daryll Clark. Penn State (7-1, 3-1) appears to have righted itself after a 21-10 home loss to Iowa on Sept. 26, but Northwestern and Big Ten leading passer Mike Kafka likely wonâÄôt go down without a fight.