Maurizio Sarri admitted Chelsea made life difficult for themselves after they reached the semi-finals of the Europa League following a see-saw 4-3 win over Slavia Prague.
With Chelsea leading 1-0 from the first leg, the tie should have been over as a contest after only 15 minutes as they sliced Slavia apart three times.
But Chelsea have developed a nasty habit of conceding early in the second half and once again there were some hairy moments as the visitors hit back twice to trail by just one on the night.
“We played very well in the first half,” said Blues boss Sarri. “But as usual in the last two months we started very badly in the second half.
“We need a solution. In the last 10 matches we started like in this match, it’s a big problem.
“Probably at the end of the first half we thought we had qualified, but against this opponent it was not true. I have never seen something like these opponents physically, so it was clear the second half could be difficult for us.
“But we did something wrong in the first 10 minutes of the second half.
“At half-time I told them to start with the same application as they started the first, but we didn’t do it. It’s not easy to understand.
“I could try without going in the dressing room at half-time if I could solve the problem.”
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