Diego Costa
Volatile Diego Costa scored the winning goal against West Ham United Getty Images

West Ham United manager Slaven Bilic thinks Diego Costa could have been sent off during Hammers' 2-1 defeat to Chelsea on Monday (15 August). The controversial Spain striker had already been booked when he fouled goalkeeper Adrian, yet referee Anthony Taylor opted not to show Costa a second yellow card.

Costa subsequently scored the winning goal in Antonio Conte's first match in charge at Stamford Bridge. "He had already been booked," the West Ham boss told Sky Sports. "I saw it again in the dressing room and it wasn't reckless and I don't think it was deliberate.

"It was quite late, the ball was already gone and he could have or should have been booked again, and that would have meant a red card. But I'm not frustrated because of that, I'm frustrated because we conceded a very late goal and that's what makes me sad."

West Ham fell behind to a penalty that Eden Hazard converted before James Collins smashed home the equaliser. But Costa popped up with a winning goal for Chelsea to deny Bilic's side in the dying moments of the match.

"When you lose a game by conceding such a late goal of course you are disappointed," the West Ham boss lamented.

"I thought we could get a point, but to be fair, from the first 15 minutes until we equalised, they were much better than us. They didn't create many chances but they were better on the ball, they were pressing and much more aggressive than us.

"They have individual class with [Eden] Hazard, Costa, Willian and more of them. We came back in the game and from 1-1 we played well. I felt we controlled the game and then, like the first goal, we made a mistake in the middle of the park when the ball was totally under control for us.

"We gave the ball away with a sloppy pass and conceded a very cheap goal."

To compound Bilic's frustration, West Ham's new signing Andre Ayew limped off with a thigh injury after 35 minutes against Chelsea and the manager subsequently revealed the club must wait to discover the severity of the problem. "We have to wait," the West Ham boss explained. "It's a thigh injury, and we have to wait until the scan tomorrow and then we will find out how long it's going to be."