Frank Lampard said Chelsea were not aggressive enough in their 1-0 defeat at Wolves.
Lampard, back at the helm following the recent sacking of Graham Potter, saw the Blues struggle to create clear-cut chances in their first match since he took over as interim boss.
They rarely looked like equalising after Matheus Nunes put Wolves ahead at Molineux with a superb first-half strike.
Lampard admitted: “You have to have more aggression in your game – more speed and more competitive duels that go your way rather than the opposition’s.
“The players have to be aware of that, because without it you can’t win games and can’t be the team that Chelsea have been and want to get back to being.
“It was interesting to see in many ways. I’m here to help with that. This is not stinging criticism, this is ‘OK, what are the reasons we maybe can be like that at times?’
“We played an aggressive team today and there were some duels that we weren’t quite at.
“And I don’t mind saying it, because it has to be said to be a reality to be dealt with.”
Chelsea remain 11th in the Premier League table and face a daunting task against Real Madrid in the quarter-finals of the Champions League next week.
But Lampard insisted there is plenty of ability in the squad despite the poor results this season.
He said: “I know there’s a lot of talent there in the squad. I’m looking forward to working more with it.
“I’m very happy to be back. I’m disappointed I couldn’t give the fans a win in my first game back.”