Thomas Tuchel seemed bemused by Chelsea's recent form as his side dropped more points in the Premier League title race by conceding a 77th-minute equaliser to draw 1-1 with injury-hit Everton on Thursday.
When asked in his post match media conference what has gone wrong - Tuchel said "I don't know."
Missing all their strikers because of the coronavirus or illness, Chelsea struggled to break Everton down until Reece James led a 70th-minute counterattack and fed Mason Mount to score for the fourth straight league game.
However, Chelsea’s recent weakness in defence was exposed again as Jarrad Branthwaite - a 19-year-old defender poked in at the far post from a free kick.
Chelsea have only won two of their last five league games and have dropped from first to third in the EPL, four points behind the leaders Manchester City.