Vlaar was recruited from Feyenoord in the summer to be the lynchpin of manager Lambert's reshaped defence.
But he has been sidelined for seven weeks with a calf problem and during that period Villa have leaked a flood of goals - 22 in the last seven games.
But the Holland international is set to play in Saturday evening's Barclays Premier League derby at West Brom ahead of Tuesday's Capital One Cup semi-final second leg meeting with Bradford.
Lambert said: "There's a good chance Ron will be back. He came through this week really well in training.
"The only thing he's lacking is match-fitness but with his muscle and the way he is, he's fine. His return could be huge and would be a big lift. He's an experienced lad and he's played a lot of big games.
"Ron was playing really well until he went out of the side injured almost a couple of months ago and it will be good to have him back."
Lambert could soon have striker Darren Bent (knee) and Richard Dunne (groin) back in contention and insists he has the experience in his squad alongside his crop of promising youngsters.
He said: "We have got experienced players here. I think some people are overlooking that. Ron is experienced, Ciaran Clark has played a lot of games now, Brad Guzan has played a lot of games. Charles N'Zogbia has played a lot of games.
"Gabby Agbonlahor has played loads of games. Because they're young, doesn't necessarily mean they've not played many games.
"With Darren and Richard, they are big players. Hopefully Richard's problem has been cured and Darren with his knee can get back quick.
"If they get back fit quick, then all the better for everyone."
It is two years since Villa owner Randy Lerner paid a club-record £24million to Sunderland for Bent plus £7million for midfielder Jean Makoun.
Lambert has already indicated those big-spending days are a thing of the past but he has no problem with Lerner's strategy.
When asked if there could be a similar type of signing to Bent, Lambert said: "No chance, none whatsoever. I think Darren came in and the lad Makoun, didn't he?
"No, absolutely not a chance. We're trying to do something within the structure of the club (in terms of signings) but we won't be able to do that.
"I get on really well with Randy. He really has been great with me, I understand where he's coming from on a lot of things and it is what it is.
"I'll work with it, and if I've got to go with the group of players I've got, then I'll go with it. I don't have a problem.
"I've got nothing but praise for these lads. They give me everything they've got."
Lambert admits he beats himself up in trying to find a solution to Villa's current plight - third bottom of the table with one point from the last five games.
He said: "It drives you mad. It drives you absolutely mental at times, like everybody else.
"I don't go home from here when I've been beaten thinking 'everything's great'. You go home and you take it, you get aggressive with yourself, but you get on with it. I'm the same as every Villa fan, I hurt like everybody else."