Chelsea defender Thiago Silva is set to miss the game against Sheffield United this weekend after injuring his thigh in the London derby on Thursday night.
The Brazil international Silva off in the first half after stretching for the ball. He was replaced by Andreas Christensen.
"It will be very tight for Sunday, only two days recovery," Tuchel said. "It is too early to give a diagnosis because I saw him very briefly with a big strap around his muscle.
Puskas, best coaches, world XIs – Who won what at FIFA awards?
"We will have to wait until Friday so we can confirm it but I think for Sunday he is a big doubt."
Jorginho's 24th-minute penalty sealed the victory for Chelsea and lifted them into sixth spot with 36 points from 22 games.
Mbappe 'really wants to go to Madrid' says ex-teammate - Euro Papers
'He lost the ball many times' - Tuchel criticises Lukaku after City defeat
Tuchel confirms Christensen will miss Man City clash after positive Covid test