Tuchel explained that while he'd like to give the almost ever-present a rest, he expects Mount to feature heavily in our final few games.
"We tried to give Mason a little break recently because he gave a lot in the Real Madrid games and he has been so decisive for us," said Tuchel.
"We didn't have much time between those games and the [Manchester] City match, particularly when you factor in the travel, but we wanted him to rest to conserve his energy and his form.
"I think he struggled a little bit in the game against Arsenal in terms of having his usual high standards and impact on the match. He has played the last few games in a double six role, which I don't think is the best position for him, but I'm still so happy with Mason.
"In the cup final, perhaps he could have played with a little more composure but don't forget, if it wasn't for an incredible save from [Kasper] Schmeichel, then he would have scored an equaliser. It wasn't to be but Mason is always a dangerous player for us and we should be careful that we don't over-expect from Mason.
"He is a key player for us in every match, he's always so decisive and that will not change for the next three matches. He is absolutely key for us."