Chelsea manager Frank Lampard believes fatigue is a reason why the team struggled against Wolves.
The Blues were underpar in the Premier League on Tuesday, and were beaten 2-1.
A Pedro Neto goal in the 95th minute sealed the win for Wolves.
It is two defeats in a row in the league for the Blues, as they lost to Everton 1-0 on Saturday as well.
Lampard admitted fatigue was part of the problem.
"There could be some fatigue. I hate to say it after a defeat because it could sound like an excuse but even the first 60 minutes when we were the better team we didn't have a zip about us," he said in a press conference after the match.
"We have travelled up to Everton, come back and up to Wolves but everyone is in the same boat on that front. At the moment we have a couple of injuries in areas that mean I can't make too many changes or rotations in certain areas of the team.
"So I understand that side of it but when you are 1-0 up and turn the result around I wouldn't say it was because of fatigue."
