Iowa running back Adam Robinson suffered a mild concussion late in the Hawkeyes' victory over Michigan State, according to sources. His availability for this weekend's game at Indiana is 50-50.
Robinson, the No. 3 rusher in the Big Ten, didn't practice Tuesday, according to sources. He continues to be monitored.
Robinson carried the ball twice in the fourth quarter and rushed 20 times for 69 yards against MSU.
On his first carry in the fourth quarter, Robinson clearly struggles after taking a helmet-to-helmet shot from MSU linebacker Eric Gordon. The play resulted in Robinson's first career fumble, which Iowa recovered. It left Robinson blinking, shaking his head and rolling his neck.
Robinson's 100.8 yards a game is third in the conference. The 5-9, 200-pound sophomore leads the Hawkeyes with 806 yards on a Big Ten-leading 172 carries.
True freshman Marcus Coker saw his first action since week 4 and carried 16 times for 40 yards. Coker could see his profile pending Robinson's health.
"But we just decided the other day, we were going to get him in there and we need to bring him along," Iowa coach Kirk Ferentz said of Coker after the Michigan State game. "He's earned that and he's worked hard in practice and I think he's caught up now from that injury [broken collarbone suffered in camp]. We're going to have to find a way to spell Adam.
"Adam continues to play really well. He just does a great job. But to play in a schedule, in a conference like we are in and a schedule like we have, we are going to need more than one guy.
"Sometimes, you need a little push. So, we got him out there. I thought he did a nice job."
Coker, a 6-0, 230-pounder, rushed for 1,698 yards and 23 TDs last season at DeMatha Catholic High School in Maryland.
After Coker, redshirt freshman Brad Rogers would be the next running back. Rogers also is the No. 2 fullback.It's unclear whether senior Paki O'Meara would be an option at running back. He's seen some limited special teams duties since suffering a concussion at Arizona.