Thomas Tuchel believes Mason Mount's performances have been affected by Ben Chilwell and Reece James' injuries which have left them sidelined.
Chilwell has been ruled out for the rest of the season following knee surgery, while James isn't expected back until the end of February at least after a hamstring tear.
Mount has been utilised on either side of the wing in the Chelsea attack, forming relationships and understandings with both Chilwell and James.
The England international has now lost that, for now, but still remains one of Chelsea's most consistent players in the attacking department.
But on Saturday was dropped as his 'untouchable' place in the side was wiped away during the defeat to Manchester City.
"I felt Mason not in the 100 per cent zone where he is like untouchable, which he normally almost is," said Tuchel. "So we took that decision and it can happen from time to time. He’s not happy about it, but it will not last long because everyone loves Mason – me included.”
Tuchel still 'loves' the 23-year-old but believes Mount is missing his club and national teammates, which has also struck off the combination of James, N'Golo Kante and Mount.
"Reece, N’Golo and him were so strong together," Tuchel explained, as quoted by football.london. "This is what we've been talking about (relationships on the pitch): when you turn, you know without even looking he will come now or I will go and get the pass and he will come in, so I will be here.
"We are missing this. And I think, without asking him now, Mason is missing this. He has this genuine understanding with Reece and with Chilly (Ben Chilwell) on the other side."
Mount is expected to start on Tuesday night when Chelsea face Brighton & Hove Albion in the Premier League.