Manchester United legend, Rio Ferdinand, has claimed that Chelsea's 1-0 defeat to Manchester City in the Premier League on Saturday was due to the absence of midfielder, Mason Mount.
According to him, the Blues missed the England midfielder's energy and bite during the game.
Gabriel Jesus broke the deadlock with a deflected strike in the 53rd minute to hand Thomas Tuchel's side their first defeat of the season in all completions.
Mount was not part of Chelsea squad for the game after suffering a minor injury in the Blues' Carabao Cup win over Aston Villa.
Manchester City are now ahead of Chelsea in the table with the victory and Ferdinand believes Tuchel will be praying Mount makes a speedy recovery.
"Manchester City have beaten a contender for the title," Ferdinand told BT Sport.
"This was a statement performance. It was a 1-0 beating today. Chelsea weren't part of the game. City dominated in all areas.
"It was really convincing and just what City needed. Chelsea weren't up to speed today, the intensity wasn't there. They were beaten by a better side on the day.
"Chelsea missed Mason Mount today, the way he connects the team and his energy.
"I think Tuchel will want him back as soon as possible."