Ahead of the Blues meeting with Malmo in the Champions League, Tuchel says he feels that Lukaku is ‘overplayed’ and might need a rest.
“It is difficult to judge whether he needs a break or is it better to keep him on the pitch,’ Tuchel said to Sky Sport.
“At this moment, I feel Romelu is a bit overplayed. I think he played in too many competitions over the summer, too many competitions with his country. He played the Nations League, and he is a fantastic athlete and such a competitive guy that he never takes it easy.
“He wants to be out there and win. He wanted to have a good outcome for the European Championship with Belgium and now in the Nations League, it was a huge match for him. It meant a lot personally to play for his country, so he takes it seriously.
“If that does not work well, he always puts it on his shoulders. He reflects on it and I feel him mentally tired.”
Lukaku has played 64 times for his clubs and his country in the last 12 months, scoring 43 goals in that period.
After a productive year with Inter Milan, who he helped win the Scudetto, the Belgian rejoined Chelsea in a club-record £97.5 million deal in the summer.
But after scoring four goals in his first four games for Chelsea this season, Lukaku has not scored in six games. However, his lack of goals for Chelsea does not worry Tuchel.
“It is not that we have a huge concern,” Tuchel added.
‘Just that he does not fully enjoy playing without a second thought. He is overplayed a little bit. This is the key point. Once he finds his rhythm and once he finds it a bit easier.
‘I feel for him and for others like Mason [Mount] and Jorginho. They struggle. They have a lot of weight to carry for their countries. They take it and they love it, but if you play a thousand matches a year, it can become a bit heavy.’
Tuchel also bemoaned the number of games players are asked to play within a short period, claiming that there are too many competitions.
“I am a big fan of quality, not quantity,” he said. “There is simply too much football and too many different competitions.”