Manuel Pellegrini admitted that he had been particularly disappointed by West Ham's opening 45 minutes as they fell to a 2-0 defeat at Stamford Bridge.
The Hammers boss admitted that, once again, his team hasn't been quick enough out of the blocks as they succumbed a a second consecutive Premier League reversal.
And for the first time, Pellegrini suggested that some of his players may not have exhibited the necessary desire or determination on the night.
"I always say the same thing to my players," he said. "If you want it, you can have it - but if you don't want it, it's impossible to do it regardless of the opposition, whether it's Chelsea, Cardiff or Everton.
"You must demonstrate a desire to play and I think we did that in the second half, but you cannot give 45 minutes to Chelsea."
You may watch Pellegrini's entire post-match press conference in full below.