Maurizio Sarri was mystified by Chelsea’s sudden drop-off at Everton and admitted a Premier League top-four finish would be ‘impossible’ if they do not improve.

The Blues dominated possession and territory in the opening half at Goodison Park, and Eden Hazard saw a deflected strike come back off a post, but the visitors faded badly after the interval.

In contrast, Everton were rejuvenated and sealed a 2-0 win by virtue of Richarlison’s header shortly after the resumption, and Gylfi Sigurdsson scoring on the rebound after his 72nd-minute penalty was saved.

The result keeps Chelsea three points behind fourth-placed Arsenal, and though Sarri was enthused by his side’s first-half display, he lamented their fragile mentality thereafter.

However, the Chelsea head coach refused to write off their hopes of finishing in the Champions League places, saying: ‘It’s not impossible, why impossible?

‘We need to recover only three points, so it’s not impossible in eight matches. It’s impossible if we are not able to improve, if we are not able to avoid a second half like that.

‘We need only to play like in the first half for the next eight matches. We played probably the best 45 minutes of the season, then suddenly at the beginning of the second half we stopped playing. I don’t know why.

‘The situation is clear, it’s impossible that the problem is a physical problem because if you have a physical problem, you can go down gradually, not in one second.

‘We continued really very well until the last minute of the first half and [were playing] suddenly very badly in the first minute of the second half.

‘It’s very difficult for the players to explain to me the change and it’s very difficult for me to explain to you the change. But probably it’s a mental block, I think.

‘I am worried about our mentality, but we played the best 45 minutes of the season.’