Frank Lampard admitted Chelsea’s performance in their 2-1 defeat at home to Brighton was unacceptable.
The Seagulls hit back to win at Stamford Bridge after Conor Gallagher had put Chelsea ahead.
Lampard said: “I’m not going to dress today’s performance up and I don’t think the players would want me to.
“I can see there’s talent in this group, but this is the Premier League and you have to have the extra bits, but we were short of those today.”
The defeat in Lampard’s first game back at the Bridge means Chelsea have lost all three matches since he returned to the club as interim boss.
“At the moment, more than defeats, it’s performance that we need to talk about,” he said.
“Wins only come with performance and in terms of the performance that was the most disappointing one, because we were well beaten.
“It’s a very good Brighton team and we must give them some credit, because they can perform like that pretty much against anyone in the league, but we were short.
“We were a yard short, a tackle short, a fighting-duel moment short, and that’s not right. You’re not going to win games like that.
“You have to have the capacity to do that as well as the desire and at the moment we’re falling short. We need to turn that around quickly.”