Kenedy has returned from a recent loan spell back in his native Brazil with Flamengo.
The 25-year-old joined Chelsea from Fluminense back in 2015 but has made just 15 Premier League appearances in his time at the club, also spending time on loan at Watford, Newcastle United, Getafe and Granada.
Tuchel plans to utilize Kenedy in a left-wing back position, where Chelsea are short on options after Ben Chilwell’s season-ending knee injury.
Kenedy has been included in Chelsea’s updated Premier League squad and has been handed the number 23 jersey.
"It's a clean slate and I think he knows it," Tuchel told reporters ahead of Saturday's FA Cup fourth-round clash with Plymouth Argyle.
"I followed Kenedy for many years, I followed him when he played for Newcastle.
"He was very promising in the early part of his career. He lost track a little bit and maybe couldn't fulfil the demands from the outside I had, but this is life.
"He gets a second or third chance to be here, and it's not about what happened. He was good in pre-season, he decided he wanted to go back to Brazil and try there. But having Kenedy and Emerson on loan, Kenedy was possible [to bring back] and now he is here.
"He is a very nice guy, very talented, and let's see where he is. It's a huge opportunity, and I am very happy to give it to him and help him make the best of it."
