“Jamie is an excellent player who has given us great pleasure. He now wants to take the next step in his career in Chelsea, and we wish him well and wish him a lot of success.”
Gitens, who joined the Dortmund from Manchester City in 2020, scored 17 goals and scored 14 in 107 matches for the club.
He will not be able to play for blues until the club World Cup.
Chelsea has already signed the Ipswich striker Liam Dlap, Briton forward Joao Pedro, Sporting Midfielder Dario Essugo and Strasburg defender Mamdou Sarr in this summer.
Estevao will also join the men of Enzo Marska after his club World Cup campaign with Villian Palmirus. He could also face blues in his quarter -final meeting with his Brazil club on Saturday.
