The 21-year-old has grabbed the chances given to him and is now among the top two CBs for the club, according to his manager. And he admits he was not expecting such a quick rise.
"Yeah, I wasn't really expecting it," Tomori told reporters.
"I came in this season trying to improve myself and give myself the best chance to play in the Premier League. Playing for Chelsea is what I've been doing since I was seven years old, so it's nice it's happened this way.
"Having the manager say that about you is nice and that's what you want. I know he has that faith in me and he's showed me that faith last year and this year.
"I've just tried to work hard and I knew coming back for pre-season I would have to take myself up a couple of levels and I was going to have to learn from other people. So, that's what I've been doing and it's nice he's saying that, but I want to carry on and keep improving."