Timo Werner has said fatigue has played a part in Chelsea’s recent dip in form.
Frank Lampard’s Blues were being talked about as title contenders on the back of an unbeaten run that dated back to September 20.
However, Chelsea suffered back-to-back defeats to Everton and Wolves to drop off the pace set by champions Liverpool.
Lampard actually played down the title talk, saying following the loss to Everton: “If it makes people who are talking about us, saying we are going to win the league, we have got the best squad in the league. It is ridiculous stuff.
"When you talk about best squads, you have to look at the teams who have won it in the last two, three, four years. Their squads are full of strikers and wingers who score 30 or 40 goals a season and midfield players who have won multiple league titles all over the place.”
The Blues can get back on track with a home match against West Ham on Monday, but it is a game Germany international Werner will head into concerned about fatigue.
“We’ve played a lot of games every three days and when you’re playing against teams who are not in Europe, they are not playing so much and have one-week breaks,” Werner told the club’s official website.
“It’s always hard because they are fit now in the moment and maybe that’s why we’ve been struggling because we are a little bit tired.
"We have a few injuries as well and we are playing with the same starting 11 in the last few games but we cannot have excuses.”
Werner, a summer signing from RB Leipzig, feels Chelsea need to learn from the recent setbacks against Everton and Wolves.
“Every team has ups and downs," Werner, who recently played down concerns about his price tag, said. “We are struggling a little but in the last two games we were not so bad to win the games.
“We have to learn from these things and do better in these games to get a draw, like Liverpool did against Fulham recently. It’s more in your favour than losing two points and that’s the style of how you become champions.”