He remains a major doubt for Saturday’s trip to Stoke.
Vlaar is still battling a calf problem that forced him off at half time during the victory at Southampton earlier this month.
It also kept the Villa skipper out of the defeats to Fulham and Manchester United.
Meanwhile, Chris Herd is set to return after missing out on the United clash with a facial injury.
Fabian Delph is back after serving a one-match ban but Gabby Agbonlahor is suspended after picking up five yellow cards.
“Ron is still struggling at the minute,” said manager Paul Lambert.
“We have to try and get that calf cleared up because he was excellent for us just before he went out injured.
“To be fair he is doing better now, step by step. We’ve just got to watch that and we’ll wait and see.
“There are one or two other little knocks that are giving us a bit of concern but we’ve still got tomorrow so we’ll see how everybody is.”
“Chris looks as if he is going to be ok which is a bonus.
“As I said afterwards, Chris was playing in the game on Sunday and we found out on Sunday morning that he wasn’t fit and we had to change the whole thing around.
“So it was a bit of a blow and it wasn’t great but sometimes that happens in football.”
Meanwhile, Lambert gave a positive update on Jores Okore.
The defender revealed this week that his recovery from a knee injury is going well – and he could even play a part before the end of the season.
“He is doing really good with his rehab,” the Villa boss added.
“Hopefully with a bit of luck he will play some part in it, but he is doing great which is a bonus.”