Green was hurt on the Texans' first offensive play in Saturday night's 19-16 preseason win over Denver.

"It doesn't look severe," Kubiak said. "We're pretty fortunate there. I'm going to list him as day to day right now. If we were in the regular season playing, we'd push it harder and try to get him back quicker. Right now, we'll be smart. The chances of him playing this week, though, I would think would be very slim."

Kubiak said the injury is similar to the one sustained by star receiver Andre Johnson in a practice on Aug. 2. Johnson hasn't practiced since, but he said he could've played in Saturday's game.

Green, who signed with Houston as a free agent in March 2007, is Houston's No. 1 running back and missed all or part of 10 games last season with a bone bruise in his left knee. The 31-year-old Green had impressed the coaching staff so far in training camp.

"It's very disappointing, after what we've been through and how important he is to the team and how good of a camp he's had," Kubiak said. "It's kind of deflating in a way. Today, we feel better about it. We know we're going to get him back."

Kubiak said the Texans came out of Saturday's victory with no other injuries.

He said the Texans could sign another running back as early as Monday to fill the gap left by Green at practice. Houston cut running back Mike Bell on Friday to make roster room for offensive tackle Torrin Tucker, who was signed after Ephraim Salaam underwent arthroscopic surgery on his knee.

Kubiak said Chris Brown, who signed as a free agent in March, will get more snaps in practice this week after seeing limited activity last week because of a sore back.