Tuchel admits he plans to give Stones every chance of making the World Cup squad.
He said: “He's obviously very upset and at the moment he gets my full support because it helps him more than putting more pressure. He was ready to play for City in the last weeks. He was ready to play.
“He played in the Champions League and he played in the FA Cup, but he was not used in the league. But he played enough for me to be important for us. So strong in training again, like every time I see him. I think he's a world-class player.
“But he has a lot of credit in the bank with me. So let's hope that he gets fit because it's most important that he finds his confidence.
“What is the exception? I don't know yet, but if you come to the World Cup you should be fit.
“So the exception of the rule means that he does not start a lot. I can see that because I'm a big fan and I know what he brings to the team in terms of personality, attitude and quality game understanding.”
The German added: “Also John Stones but he had injuries so he needed to come in camp. I needed to meet him in person to see how he acts within the group. It will be interesting now to see how he acts within the group. He will stay with us.
“Like I said, he has an asset. of course, that he can also be super-important in a tournament, in knockout football, in defending a lead and chasing a game with crosses and long throw-ins. and set-pieces.”