Villa have taken just one point from five games, a run that has seen them drop into the relegation zone, and have conceded 22 goals in their last seven matches, scoring just four times in this period.
Lambert feels that he may have to use the loan market to bring in new signings, with a large budget out of the question.
"There is a chance of no signings at all. There is also a chance you might try and get someone in, so it works both ways," Lambert said.
"We'd try to do something if I thought the people we could get in would make it better.
"But if we can't do it, and I have to go with the group that's there, then I'll go with what's there. What I don't want to do is fill the place with people I'm bringing in just for the sake of bringing them in.
"A £15m spending spree is not on the agenda, nowhere near it.
"Loans are not something I'd disregard. I'll just have to wait and see on that as well."
Aston Villa's most expensive January signing was the £24million purchase of Darren Bent two years ago.