Tate Forcier suffered a mild concussion on his last play prior to being replaced by Denard Robinson.
Yesterday, Rodriguez explained: "I don't think it was a severe one, but he still has a headache. The doctors and trainers tell us each day and each week who's available and who's not available," Rodriguez said. "We would never put somebody out there who's not 100 percent."
Forcier is also suffering from a persistent shoulder injury. Rodriguez said the injury has limited Forcier in practice the last few weeks. He also suggested the injury may have led to several of his rookie mistakes against MSU and Iowa.
Rodriguez made clear though that the concussion was not the cause of the last-minute replacement.
"I was putting in Denard anyway," Rodriguez said.