Alex McLeish feels Alexander Hleb has been 'embarrassed' at times during a difficult season at Birmingham.
The Belarusian playmaker arrived at St Andrews on a season-long loan over the summer boasting a sizeable reputation shaped at Arsenal, Stuttgart and Barcelona.
Much was expected of him, with his return to England seen as a quite a coup for the Blues.
He has struggled to produce his best, though, with a lack of match sharpness and Birmingham's tactical approach holding him back.
McLeish admits that Hleb has been given a rude awakening in the Midlands, with his omission from the starting line-up for the Blues' shock win over Chelsea proving that he is not untouchable.
He responded with arguably his best showing for the club in Saturday's 1-1 draw with Fulham and has been informed that he must maintain those standards if he is to tie down a starting role.
McLeish said: "I've repeatedly told him that he is not fit enough to start games.
"He was disappointed not to start against Chelsea. He thought it was a slight and was a bit embarrassed by that.
"A top player thinks he can just walk into the team - but it doesn't work like that."
McLeish has also called on £6million summer signing Nikola Zigic to add more aggression to his game.
The towering striker has looked more comfortable over recent weeks, having started to settle in England, but his manager feels there is still plenty more to come if he works on the right areas.
The former Scotland boss said: "For such a big guy, the aggression is not in his game.
"He is a passionate guy but we've tried to put aggression in his game and he is getting better.
"It is about telling him to attack the ball because in Europe he probably only heads the ball three or four times in a game, and it's the same with Serbia.
"He is used to the ball being played on the deck but we want him to become more aggressive."
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