Jose Mourinho, though, is concerned there remains a gap in the Spain striker’s education.
The Chelsea manager’s concern is that Costa appears to be collecting yellow cards with the same ease with which he has been finding the net. And while Steve Bruce, the Hull manager, was understandably the more vociferous of the two managers when it came to assessing the performance of referee Chris Foy after the game, Mourinho had his own gripe about the match official after Costa picked up his seventh booking of the season.
Once again the forward was cautioned for simulation, and once again Mourinho was convinced Costa had been hard done to. Certainly the striker’s infringement was nowhere near as obvious as the dive that sent Gary Cahill, the Chelsea centre-back, tumbling to the ground moments earlier.
Foy decided the England centre-back had tumbled to avoid a collision with two Hull players, sparing Cahill the second yellow card that would have forced the home side to play with 10 men for over half an hour, and triggering an angry outburst from Bruce.
Mourinho tip-toed around that issue, trotting out a variation on the familiar line that Cahill was not that kind of player. But he was more forthright about the treatment of Costa that, he believes, is becoming a trend.
The forward has already served one suspension this season and three more bookings would force him to sit out two matches. And with the title race developing into a much tighter contest than it was during the opening weeks of the campaign, Costa’s absence could prove costly.
“I can’t believe it,” said Mourinho when asked about Costa’s disciplinary record. “I remember two that are understandable and fair. Everything he does is a yellow card.”
The Chelsea manager believes his player of the reputation he earned at Atletico Madrid. “When he was Atletico he created a certain image, and people don’t believe that he can change,” added Mourinho. “People don’t believe the way we teach him what England is — the mentality, what people accept, what people don’t accept, what is a red card. People don’t understand that he is intelligent enough to understand it. And to change — because he changed.”
Costa’s more significant contribution was the 68th-minute goal that wrapped up a victory that was made all the more comfortable by Tom Huddlestone’s dismissal on the hour for a studs up challenge on Felipe Luis, a challenge, Bruce insisted, that was borne out of the frustration at seeing Foy fail to dismiss Cahill.
Up to that point Hull had battled gamely, if ineffectively, and never looked likely to recover after falling behind to Eden Hazard’s seventh-minute header.
For Chelsea, this was a return to stability after the previous weekend’s defeat at Newcastle and maintained their three-point lead at the head of the Premier League after Frank Lampard, their former player, had secured three points for Manchester City at Leicester.
It would be easy for Mourinho to view Lampard’s impact at the Etihad Stadium wistfully but the manager insists he has no regrets about the player’s departure from Stamford Bridge and maintains it was more important to retain the services of John Terry and facilitate the return of Didier Drogba.
“The project is prepare for the next 10 years not for the next year we made the right decision,” said the manager. “You can argue ‘you have John Terry and Didier Drogba’. Different: Didier is a striker that is coming to help and support and John Terry is the best central defender in English football and it doesn’t matter how old he is and the nucleus of the team that has to be developed. A big player like Frank we would stop the development of the other guys.”
Defeat extended Hull’s dismal run to nine games without a win. Bruce’s side sit second bottom and the manager has had the sideshow of Hatem Ben Arfa to deal with. The on-loan Newcastle winger has reportedly decamped to France after falling out of favour and Bruce concedes the Frenchman may be a lost cause.
“Sometimes transfers work out and sometimes they don’t. And it’s fair to say that with Ben Arfa I can’t see there being a future,” said the manager.
“There has been no fallout, he’s been omitted from the squad because when you are up against it, then I believe you need to show a bit of resilience, and unfortunately Hatem see it differently.”
CHELSEA (4-2-3-1): Cech 6; Ivanovic 8, Cahill 5, Terry 7, Luis 6; Matic 7, Mikel 5 (Ramires 81, 6); Willian 7 (Schurrle 80, 6), Oscar 6 (Drogba 78, 6), Hazard 9; Costa 8.
HULL CITY (3-5-2): McGregor 7; Dawson 6 (Bruce 10, 7), Davies 7, Chester 8; Elmohamady 6, Meyler 7, Livermore 6, Huddlestone 4, Robertson 6; Jelavic 7 (Ramirez 65,6), Aluko 5 (Brady 64, 6).
Referee: Chris Foy 5.