Chelsea boss Jose Mourinho is struggling to to find the solution to their inconsistency after Capital One Cup elimination by Sunderland.
Mourinho suggested his current crop were a better footballing side than the one he stewarded during his previous spell at Stamford Bridge, but was at a loss when asked to explain why there is an absence of offensive potency.
"I cannot answer this question," he said.
"I think we are in front in terms of quality of the game.
"It's about results about scoring goals but you see every game we are in trouble."