He is looking to make the necessary changes to take all three points from a Cardiff City side that's unbeaten since November.
"We will certainly look to freshen it up against Cardiff," said McLeish. "We have players to come back, players who have good speed, who can make a difference.
"I'm trying to change the dynamic of the team for this half of the season.
"I'm really disappointed to be out of the FA Cup but I've got to say the odds were stacked against us given the personnel problems. There were eight players missing against Wolves who could conceivably start in the team.
"Whether I will have them all available, because there are still one or two injury concerns, remains to be seen.
"The other ones, Bouazza, Bowyer, Sinclair, are all in contention. So we can make changes, get the fresh legs in and have a real go at Cardiff."