Updated at 4 p.m.

BEREA, Ohio -- Browns running back Peyton Hillis will be out at least a couple of weeks after re-injuring his hamstring in practice today, a source said.

An MRI this afternoon revealed that he significantly aggravated the muscle.

It happened early in practice on a run up the middle.

Hillis came up limping on the play, grabbing at his left hamstring.

He fired the ball to the ground, then threw his helmet down in frustration.

He limped over to the sidelines and stood talking to one of the team trainers with his head down and his hands on his hips. He then limped halfway down the practice field for further examination by the trainer.

Browns coach Pat Shurmur said that Hillis would have an MRI today and his status would be updated afterward. Shurmur added that if Hillis is not ready, "we'll move on."

Shurmur added that it's up to Hillis to do everything possible to get back to where he can play as soon as possible.

Hillis, who sat out the past two games with the hamstring injury, had returned to practice on Thursday and was expecting to start on Sunday in Houston.

Now, with Montario Hardesty out with a torn calf muscle, newcomer Chris Ogbonnaya will start against his former team and newly-signed Thomas Clayton will play as the third-down back.

Ogbonnaya was signed Oct. 18 off the Texans practice squad and pressed into serve five days later against the Seahawks. He played well that game and then was thrust into the featured role last week in San Francisco when Hardesty tore the calf muscle.