Faulkner accepts Villa got it wrong in appointing McLeish as Gerard Houllier's successor after the Frenchman left the club on health grounds last summer.
"It's using hindsight. We've had to make the change with Alex now and you're constantly evaluating yourselves," Faulkner said.
"The season didn't go the way we would have wanted and we have to look for reasons why that may be.
"If we were happy with mediocrity or a season like this, then we wouldn't be making changes."