Chelsea interim boss Guus Hiddink has spoken to Diego Costa after his dismissal at Everton and hopes the striker can learn to control his volatile temper.
Costa, who has scored 11 goals in his last 16 games, 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 through suspension.
He had until Thursday at 6pm to respond to a charge of improper conduct following his reaction to being shown red by referee Michael Oliver. It is understood the verdict will be announced next week, but, if found guilty, his suspension could be extended.
Costa avoided further sanctions. He had no case to answer over a half-time gesture and was absolved of a bite on Gareth Barry after the Everton midfielder insisted nothing untoward had happened during their altercation.
Hiddink said: "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.
"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 described the incident with Barry, during which Costa nuzzled into the Everton midfielder's neck, as a "kiss or bite, however you mention it". The Dutchman suggested the gesture allegation was made to target Costa.
"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."
Costa has played a significant role in guiding Chelsea clear of the lower reaches of the table since Hiddink succeeded the sacked Jose Mourinho in December.
The Dutchman added: "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."
Hiddink denied Costa's omission from the Spain squad for the friendlies with Italy and Romania was due to his disciplinary issues, instead insisting it was a result of an ongoing hip problem which will be treated during the international break which follows the West Ham match.
"It was a medical issue by the Spanish coaches and medical team," Hiddink said.
Eden Hazard will also miss the Hammers clash and Belgium's international with Portugal due to a hip and groin problem.
Hazard's fitness and form have perplexed Chelsea this season and Hiddink hopes the enforced rest will benefit the 25-year-old.
Hiddink said: "He still has discomfort in this area. It's good for him. Of course, first for Chelsea after the break, (to) see if he can get fit to participate in the last league games.
"It'll be good for him and Belgium to make sure he starts the Euros in good physical fitness."
The absence of Costa and Hazard could see Alexandre Pato make his long-awaited debut. The Brazilian joined on a six-month loan from Corinthians during the winter transfer window, but is still to make his debut.
Hiddink ruled out Pato's loan being cut short despite the absence of game time.
"At this moment, he will stay until the end of the season, yes," Hiddink said.
Radamel Falcao is back in training following a thigh injury sustained in October but will not be considered until after the international break.
Hiddink is wary of West Ham, who are fifth, two points behind fourth-placed Manchester City, entering this weekend's fixtures, but have not won at Stamford Bridge since 2002.
"They are in a mood now and so statistics about the past don't say much to me," he said.