The centre-half was a key figure in the Villa side last term, but has faced accusations that the injury to Martin Laursen impacted on his own performances.
The former West Brom defender has responded to his critics and is confident he is worthy of his place in Martin O'Neill's team.
"I think it is funny when people say, 'Am I good enough?'," said Davies in the Birmingham Mail.
"I don't think the gaffer would have signed me if I wasn't good enough.
"I played 45 games last year. Would I have played that many if I wasn't good enough?
"I am sure the manager would have found me out by now. But it is up to people to think whatever they want.
"The main thing for me is to go out there and to play whatever is in front of me."