Guus Hiddink has asked Diego Costa to control his temper after the volatile Chelsea striker's red card at Everton last weekend.
Costa was sent off for the first time as a Chelsea player in last week's FA Cup loss at Goodison Park and will miss Saturday's Premier League clash with West Ham United through suspension.
The Spain international was dismissed for clashing with Gareth Barry and then briefly made contact with the Everton midfielder's neck before appearing to change his mind about biting his rival.
Costa also had an angry exchange with referee Michael Oliver and was hit with a Football Association charge of improper conduct that could lead to his suspension being extended if he is found guilty next week.
It is not the first time the fiery former Atletico Madrid star has been in trouble during his time in England following bans for clashes with Liverpool's Emre Can and Arsenal duo Laurent Koscielny and Gabriel.
Hiddink is determined to help Costa keep his cool better in future and the Blues interim boss sat down with the player to try to resolve the issue this week.
"I talked to him and we talked many times about him playing on the edge and his reactions. We were happy and are still happy with his performances," Hiddink told reporters on Friday.
"What we all like, but not going over the edge, is to play as he is doing, with a lot of blood. Whether or not bit by bit (he is) provoked, he has to control himself. He knows (that).
"If he reduces what he did more frequently in the past, we are progressing. We have to have hope."
Hiddink defended Costa over the bite allegations, which Barry later refuted, and suggested claims the Chelsea forward made a crude gesture to Everton fans was typical of a campaign against the star.
"First everyone wants to go on his kiss or bite, however you mention it, but Barry made a very good statement by saying what has happened or not happened in this case," Hiddink added.
"Maybe there was a little bit of searching for Diego, 'Where can we get him?'. There he was frustrated.
"He desperately likes to play. He accepts he's suspended and is not happy with that.
"He also is contributing a lot to the little bit of a resurrection after December, when we started. That's why I defend him and I like him very much."
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