Chelsea head coach Maurizio Sarri says his team have a "mental problem" in their approach to matches.
Sarri is yet to taste defeat since replacing compatriot Antonio Conte, breaking a Premier League record for the longest unbeaten run by a coach new to the division.
Chelsea are four points behind leaders Manchester City but have stumbled of late, held to a 0-0 home draw by Everton in their last Premier League match after battling to a 1-0 away win over BATE in the Europa League.
And Sarri feels that if Chelsea are to have a chance of closing in on last term's runaway champions they must solve issues with their mental preparation.
"I think it is a mental problem. In the last three matches we had a problem with the approach of the match," Sarri told a news conference ahead of Saturday's trip to Tottenham.
"We have to be careful and be focused on this problem. For sure it is not a physical problem, it's a mental problem. We have some difficulties to enter the match. It is not a tactical problem.
"In the first 15 minutes of three matches the problem was the opposition was more aggressive and determined than us, so it's not a tactical or physical problem. We have to approach the match in a different way."
Sarri has regularly dismissed Chelsea's title chances and he expects a tough battle for Champions League qualification in his first season at the club.
"I think there is a team above, which is Manchester City, then a very good team in Liverpool. For sure, Liverpool will be in the first positions," he added.
"Then four or five teams that will have to fight for the Champions League positions - Arsenal, Tottenham, United, someone else. Sometimes, usually there is a surprise.
"For me they [City] are stronger than us at the moment and we have to work, work very hard to try to recover the gap, but at the moment the gap is still there. We have to do it. We can recover but I don't think in the first season we can recover 30 points [the deficit between the sides last season]."
Chelsea head to Wembley a point and a place above Tottenham in the Premier League table and Sarri lauded the progress made by their London rivals under Mauricio Pochettino.
"He is doing a very good job. They play very good football," Sarri added. "They are very dangerous in the offensive phase and with short counter-attacks, a technical team.
"In the match they run a lot, from the physical point of view they are a very strong team, are competitive and they will fight for a Champions League position for sure. It's a very difficult match for us.
"We have to make sure we don't lose the ball in our half. They are very, very dangerous in these situations."
