The England international, Villa's top goal-scorer for the last two seasons, has been left out of the previous two starting line-ups behind summer signing Christian Benteke.
Reports since have suggested a fall-out between the pair, but Lambert claims they are wide of the mark.
"I've never had a problem with Darren, I have a laugh and a joke with him,” said the Scot.
"Of course, I understand people get frustrated when they are left out. You'd be more worried if they weren't. But he has not been knocking on my door. There was never a problem.
"As for people saying we are not talking, I don't worry because I know it's not true.
"I try to be fair and honest with everyone. I don't rule with fear if that is what people think. I treat people the right way and respect them. I don't do anything untoward.
"My job is to pick a team that will win us a game. That is my job and that's what I try and do for this football club.
“I trust the lads to perform. That's the great thing I've got but I can't keep everyone happy all the time.”
By Joe Brewin
