Thomas Tuchel said he had little choice but to replace Saul Niguez at half-time after spotting some ‘big mistakes’ during his Chelsea debut against Aston Villa.
Saul joined the Blues on a season-long loan with the option to buy in the final hours of the summer transfer window.
The 26-year-old came straight into the starting XI on Saturday evening against Villa but was replaced by Jorginho for the second-half.
Explaining his decision, Tuchel told Sky Sports: ‘Well, it was hard to do it but I had the feeling he struggled, he had some big mistakes, passing mistakes and errors and he struggled with the intensity and you could see that he has not fully adapted.
‘So it is completely my responsibility, I thought that he can maybe just jump in and play for us on that level.
‘So I thought it is maybe just better to have Jorginho who has a close connection with Thiago [Silva] to control the game there a bit more.’
Tuchel added in his press conference: ‘It was a hard decision.
‘I take responsibility for that. I put him into a difficult match after the international break and it was hard for him to adapt in genera for him to the intensity.’
Chelsea’s win moves them joint top of the league alongside Manchester United with both sides on 10 points.