McLeish revealed Hleb has been able to train for less than 20% of the time available to him since his temporary move from the Nou Camp two moths ago.
He has been affected by injury niggles but also a lack of pre-season action and looked a shadow of the player who was a key performer at Arsenal. McLeish even left Hleb out of his starting line-up for the midweek 3-2 at Stoke and he remained on the substitute's bench for the entire 90 minutes,
McLeish told Press Association Sport: "Alex knows he is a big-time player and there are high expectation levels on him. He has got a reputation to preserve but he is not fully fit. He is not 100%. If Hleb was fully fit, we know he would be shrugging off the challenges on him. If we can get him top fit, we know that he will be a different player and a player who can make a difference. But I've got to do what is right for the team."
McLeish revealed: "Alexander has been here 70 days and only trained for about 13. We have to get that statistic higher to make sure he is at a level where he is going to make a difference for this football club. It just little niggles all over.
"The pre-season is crucial for players. If you don't get the right pre-season, the season can become a struggle for them. They can pick up niggles and Alex did not have much action pre-season at Barcelona. He said he did all the training but games-wise he didn't do much. He is about 12 games behind these guys here."