It is harder for English clubs to be in “top physical condition” at this stage of the season than teams in Spain or Italy because they “have to play more”, says Chelsea boss Maurizio Sarri.
The Blues are fourth in the Premier League, one point ahead of Arsenal and three ahead of Manchester United, who host them on Sunday (16:30 BST).
Both Chelsea and Arsenal are also in the semi-finals of the Europa League.
Sarri said the number of matches was a “problem” for English clubs.
“Probably Spanish or Italian teams, in this moment of the season, will have played 48, 49, 50 matches… Here in England, we will play match number 57,” he said.
“To have seven to 10 matches in difference at this stage of the season is a big difference.”
From 2 May, Chelsea will play three matches in seven days, with both Europa League semi-final legs against Eintracht Frankfurt taking place either side of Watford’s visit to Stamford Bridge in the league.
“After 55 or 56 matches, playing every three days, it’s very difficult,” added Sarri.
“It’s a problem. It’s not easy for an English team to solve this problem. It’s very difficult to arrive at the final part of the season in top physical condition.”
Hudson-Odoi ‘out for three months’
Sarri revealed that injured Chelsea and England winger Callum Hudson-Odoi will be out for three months after surgery on a ruptured Achilles tendon but will “come back better than before”.
Hudson-Odoi played 24 times this season and made his England debut in March.
The 18-year-old was taken off in the 41st minute of Chelsea’s 2-2 draw with Burnley on Monday night, in what was his fourth league start of the season.
“He’ll need time now, but Callum is a very strong young man,” said Sarri.
“Very strong physically, and very strong mentally. I’m sure he’ll be able to come back better than before.”