HOUSTON -- The Houston Texans have lost running back Arian Foster for the near future as he gets set for groin surgery.

Exactly how long he'll be gone, we don't know yet, but his absence will last into the regular season. That will call into focus the Texans' other running backs, namely Alfred Blue, Chris Polk and Jonathan Grimes.

Blue took over in practice Wednesday in Foster's absence. As things stand right now, he's the Texans' starter.

"I’m a better runner," Blue said, when asked what he's improved on. I’m more patient, learning from Arian and him mentoring me, critiquing me every day at practice. Just teaching me how he runs and what he’s seeing out there when he is running. I would say I’m much improved in that.”

We've so far been talking about Blue as mostly a first- and second-down back, but he's been working on being more versatile. A few months ago, Foster said he was working to turn Blue into a three-down back.

Texans coach Bill O'Brien agreed that Blue's running has improved and he also noted improvement in blocking and blitz pickups.

"Blue can play on third down in certain third-down situations, no doubt about it," O'Brien said.

Polk has been sidelined with a hamstring injury for the past few days, but he'll definitely be in the mix to help there once healthy. Polk is a powerful back who had a good game against the Texans last season when the Eagles visited Houston. He's also a good returner, something the Texans are trying to sort out. This is a video of Polk's 102-yard kickoff return last season against Washington.

O'Brien also singled out Grimes as having had a strong day of practice Monday night and said he wasn't limited to being just a third-down back.

After his visit, the Texans did not sign Pierre Thomas. Right now, the running backs on the roster have a big opportunity.