No Chelsea player has more than the midfielder's 2,230 Premier League minutes so far this campaign, yet Tuchel is not concerned about burnout in the 22-year-old ahead of the run-in.
"Once I see him without that big smile on his face or without the sparkle in his eyes then maybe I'll have to think if the moment has arrived where he plays too much but right now I feel he is very excited about the situation," said Tuchel.
"He is very mature, which is quite impressive, and that's why I'm not worried at the moment. He's a super reliable player for us, shows top quality, is very strong under pressure in the games and he can deliver every three days.
"I don't want to talk too much about him being tired because I can feel him very relaxed. Even if he's physically tired, I feel him mentally totally clear and that is what's very impressive for me.
"This is maybe the key factor that he can have a big career because he has both feet on the ground. At the moment, he's in a good place."