Mount put in an assured display as the Blues claimed a crucial 1-0 away win against Atletico Madrid in the Champions League.
Tuchel's side nabbed a first leg advantage to take to Stamford Bridge, with Olivier Giroud getting the only goal of the game.
However, Chelsea will be without Mount for the second leg, as he is suspended.
"Don't forget Jorginho, we will miss two crucial players [in the second leg], it makes things not easy for us," Tuchel said at Arena Nationala.
"I am very happy with the performance of everybody, that includes Mason of course.
"Again, a good effort, a big effort, high work rate, high intensity like we are used to when he plays like this. He has a big impact on our team. Honestly, we now play Man Utd, Everton, Liverpool and Leeds, it is good like this.
"We cannot get comfortable; we cannot get lazy. These games will push us to our limits, then we will think about our solutions for the second leg."