Villa v Southampton injury news: Vlaar resumes training
Goalkeeper Shay Given is also a doubt with a hamstring injury.
Vlaar has resumed training from a long-standing calf problem, although the Saints encounter may come too soon for the Dutch defender.
Westwood is back in contention after hurting his ankle ligaments at Swansea on New Year's Day, while Holman has recovered from the virus which kept him out of the cup ties against Ipswich and Bradford.
The knee injury Bent sustained in a collision with Bradford keeper Matt Duke is not as bad as first feared but the striker is expected to be out for around 10 days.
Albrighton has a metatarsal injury while Herd also has a foot problem.
There is positive news, though, on Richard Dunne who could resume training next week.
"Darren isn't as bad as first feared but he is going to be out for Saturday," said manager Paul Lambert.
"It is his knee from the collision with the goalkeeper. It is not as severe - maybe 10 days. It's his medial ligament.
"Shay is struggling with a hamstring as well.
"Ron trained a little bit yesterday so hopefully he will have no adverse reaction and he might join in this morning. That is a plus.
"I don't know if he'll be in from the beginning as he hasn't done enough until yesterday but he is round about.
"Chris Herd is going to be out for a few weeks with his foot and Marc Albrighton is out so there are one or two injuries still there.
"Richard might training in the middle of next week - we'll see how he does."
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