Chelsea coach Thomas Tuchel said after losing 1-0 to Everton on Sunday that he may not finish the season in the top-four if he continues to achieve mixed results in his last four Premier League matches.
Everton striker Richarlison scored the only goal of the match, leaving third-placed Chelsea to collect only 4 points from their last 4 games.
The Blues are 3 points ahead of fourth-placed Arsenal, and 5 points ahead of Tottenham in the Champions League qualification race.
"I said several weeks ago that I did not feel safe, and we were never safe," Tuchel told reporters. "If we are in a race for first place, first two places or first four places, and regardless of the race itself, if we get 4 points from the last 4 matches It's never enough."
"We have to take care of ourselves. At the moment we don't get points when we play well, we deserve more, and we lose when we play well. This is a bad combination."
Richarlison's goal came after a mistake by Chelsea captain Cesar Azpilicueta to clear the ball, and the German coach said his club was paying the price for committing major mistakes in recent matches.
"We knew what awaited us and how things would play out in the last matches. We struggled to get a clean sheet. In the last 4 games we came out (one clean sheet) once against West Ham United. That was the only win and I'm very disappointed," Tuchel said.
"What can I do? The ball was easy and we missed a goal and that's the worst thing that can happen. This happens a lot. We struggled to play without big mistakes and that's why we struggle to get results."
The London team hosts its rival Wolverhampton next Saturday.