The team announced Larkin's retirement Monday after the sophomore saw three specialists last week to confirm the diagnosis, which is not life-threatening. He had started experiencing symptoms in the past two weeks.
"Football has been a lifelong passion and it has been a process to reconcile the fact I won't be on that field again, given I've played this game since I was five years old," Larkin said in a statement. "I'm extremely appreciative of the Northwestern sports medicine and athletic training staffs for uncovering this condition, and for my coaches and the medical staff for always putting my health first. I came to this university to engage at the absolute highest level on the field and in the classroom, and I'm grateful for the opportunity to continue one of those while supporting my teammates from the sideline."
Wildcats coach Pat Fitzgerald said he was informed Friday that Larkin would need to retire from football. He said it could have been "catastrophic" if Larkin had continued to play and that the diagnosis, before severe damage occurs, is "the best possible outcome."
"Obviously a challenging day for Jeremy Larkin the player, but a blessing for Jeremy Larkin the young man," Fitzgerald said.
Larkin had 346 rushing yards, 19 receptions for 127 yards and five touchdowns in the first three games for Northwestern. He had logged 72 of Northwestern's 110 carries this season.