Updated

Iowa coach Kirk Ferentz said Tuesday that running back Jewel Hampton will have knee surgery and is likely gone for the rest of the season.

Hampton, a redshirt sophomore, hurt his left knee in the second half of Saturday's 34-27 loss at Arizona.

Hampton, who missed all of last season after tearing the ACL in his right knee, had been splitting carries with starter Adam Robinson, rushing for 114 yards on 27 carries this season.

Ferentz wouldn't say whether Hampton had suffered another ACL injury, but stressed that his surgery will require ample recovery time.

"He's very disappointed. He's invested a lot. He's one of the competitive guys on our football team," Ferentz said. "It's not the end of football life, necessarily, but it just feels that way and it's going to feel that way for a couple of days I'm sure."

No. 18 Iowa (2-1) opened fall practice with three experienced sophomore backs — Hampton, Brandon Wegher and Robinson — and only so many carries to go around.

Now nearly all of them will go to Robinson.

Wegher left camp because of personal issues and isn't expected to return this season. Robinson assumed the starting job after Hampton was suspended for the opener, but the two began rotating every series in a 35-7 win over Iowa State.

Robinson broke Iowa's freshman record with 834 yards rushing in 2009, and he had a team-high 270 yards rushing and four touchdowns this season. He rushed for 109 yards in a season-opening win over Eastern Illinois, though he acknowledged Tuesday that was he a bit gassed after 24 carries.

"I just have increased responsibility to my team now," Robinson said. "I'm just going to have to get a lot of sleep and get rested up because I do now I was getting tired toward the end of the third quarter into the fourth quarter in that first game."

Freshmen Marcus Coker and De'Andre Johnson will serve as backups starting with Saturday's game against Ball State (1-2), though Ferentz would like to keep one of them off the field, most likely Johnson, so they don't burn their redshirt season.

"Right now, we just have to prepare as if everybody's going to play, and then we'll go from there. We want to win this year, too," Ferentz said.

Ferentz also said Tuesday that backup linebacker Bruce Davis will likely miss the rest of the season with a knee injury.