The striker featured in all but one of Villa's opening 12 fixtures this season but has not made the squad at all in November.
Summer signing Christian Benteke has been preferred in the main striking role while youngster Jordan Bowery has been selected on the bench ahead of Bent.
There has been much speculation for the reasons behind his absence with rumours he has handed in a transfer request and that he is being frozen out to prevent triggering a £3m payment to Sunderland when he reaches 50 league appearances.
But Lambert said: "Have there been any enquiries for Bent? No. Has he asked to be put on the transfer list? No. Is there a clause? That's not true. I'm not sure where that came from.
"I see what happens every day in training. It's not about people not putting in the work. You've got 20-odd guys which are in the same boat with each other.
"I think the team that I pick will be the team that will try and go and win us a game. It's the way I've always done it and it's the way I will always be.
"As I said, with Jordan Bowery the potential is extremely high and he's an unknown quantity which works in our favour."
The Villa boss also heaped praise on Benteke and tipped the Belgium international, 21, to have a stellar career.
"I think he has really good manners and he's really humble which is a great thing for a footballer," said Lambert.
"If he keeps that way he will have a massive career. He's given us everything he's got and his work ethic is fantastic for us."
Villa take on fellow strugglers QPR this weekend and Lambert is not underestimating the effect that the arrival of new manager Harry Redknapp will have had on the west Londoners.
"Harry going in there will automatically give them a lift as he's a brilliant manager," he said. "But we'll certainly go there and try and win. We're playing well enough to win.
"The onus is on the home team to make the running. They'll come out of the blocks and we have to be ready for that."