Asked for news on the fitness of Kovacic and Ziyech, Tuchel replied: "I don't know. I should have subbed Mateo Kovacic at half-time so could have had one more change.
"I have not spoken to the doctor about Hakim and hope it is not serious.
"Today is Tuesday, there are a lot of days to recover until Sunday. We don't like to have that many injuries and more impact from the bench on a tactical matter.
"I hope they will be ready for Sunday."
On the match itself, Tuchel added: "With away goals, it would be better! We have another clean sheet. It was well deserved, it was hard work to not allow chances, they were a strong opponent.
"There was a little bit of up and down, some very good moments, some weak moments, but we never gave big chances away. A tough game but a deserved win. We were a bit passive and too deep, and we suffered in ball possession. But we kept the belief, we fought back, and scored a very good second goal."