Dumped out of both cup competitions by lower league opponents last week, Villa's only remaining target this season is to avoid relegation.
Lambert's side sit just one point above the bottom three, and his reliance on a core of players relatively untried in the Premier League has brought calls from supporters for new, experienced signings.
But with little time left to strengthen his squad, he said: "At this minute there's not much really happening. There's been guys we went for who have gone to other clubs.
"How many players are we short? There's a few. But I knew the remit of the job was to rebuild. To rebuild something you have to strip it right back.
"But if you are asking me if there will be a vast amount of money available during the rest of the transfer window, there won't be."
Lambert insists owner-chairman Randy Lerner remains fully committed to the club despite the limited funds available.
The Scot said: "Has Lerner washed his hands of Villa? No, the one thing is he's not washed his hands of it.
"If he has got other commitments, that's entirely up to himself, if he has got other things on.
"But he's definitely behind the club. He wouldn't have done what he's done if he wasn't committed to it."