The 20-year-old, a right-footed winger capable of playing on the left, is seen as a priority target for Chelsea as they look to strengthen their squad during the brief transfer window created ahead of the expanded 32-team tournament. Talks progressed after representatives from both clubs held discussions on American soil.
Chelsea have already seen two bids rejected for Gittens earlier this month, with Dortmund reportedly demanding a fee in excess of 50 million pounds for the England youth international.
Gittens enjoyed a breakout season last year, scoring 12 goals in 48 appearances across all competitions, including four in the Champions League.
His pace, directness, and versatility have made him a sought-after option for Chelsea, who continue to target dynamic attackers capable of operating across the frontline. The Blues believe Gittens fits the profile and are confident a deal can be reached.
Meanwhile, Chelsea have made a strong start to their Club World Cup campaign, defeating Esperance de Tunis 3-0 to book their place in the round of 16.
Young striker Liam Delap netted his first goal for the club in that match, providing further encouragement for manager Enzo Maresca.
Borussia Dortmund secured their place in the FIFA Club World Cup knockout stages with a hard-fought 1-0 victory over Ulsan HD in Group F, thanks to a clinical first-half goal from Daniel Svensson.
Chelsea bounced back from defeat to trounce Esperance de Tunis 3-0 to cruise into the last-16 of the FIFA Club World Cup on Tuesday.
Manchester United and Chelsea are reportedly exploring blockbuster moves that could see Alejandro Garnacho and Christopher Nkunku switch clubs, as both players seek fresh starts after turbulent seasons.
Liam Delap is refusing to be fazed by the weight of Chelsea's number nine shirt as he prepares to lead the line in Tuesday's crucial Club World Cup group-stage clash against Esperance de Tunis.
