The 31-year-old watched from the sidelines as the Blues won 2-1 against Club America in Las Vegas.
His £33million transfer from Napoli is a world record for a player over 30, but Tuchel has supported the Senegalese international to remain at the highest level for years to come.
“That’s what we believe and that’s what he’s here for,” Tuchel said at the Allegiant Stadium. “There were always rumors that he was going to leave Napoli and it was always super difficult – and ultimately impossible – to get him because he was an important player.
“It’s nice that he is up for the challenge now and we have Thiago Silva, who is even older and super experienced and still at the peak of his game. We hope that Kalidou can do the same and play for us for many more years to come.”
“He is completely fit and ready for the challenge and he should be because we need him in top form.”
The Blues squad has also been bolstered by Raheem Sterling, who was in on a £47.5 million transfer from Manchester City, while talks are underway to sign Paris Saint-Germain’s Presnel Kimpembe and Sevilla’s Jules Kounde.
There are also a number of returnees who want to impress, namely Conor Gallagher. And Tuchel was impressed by the England international against Club America.
“Conor trains at a very high level and you can clearly see that it was the right decision to loan him,” he added.
“He made a huge step in his development at Crystal Palace and became an England player. We can see this clearly in training, it was a very good start and a good match for him.”
“For him, he has to get used to our game principles, to understand when to move and when not to, and his pace of work is excellent and he has such a big heart. He can be a great asset to us.” “