The 20-year-old has made 11 first-team appearances for the Red Devils during the 2019-20 campaign although just three of those outings have come in the Premier League.
Earlier this month, it was reported that Bremen were in talks over a move for the Netherlands Under-21 international, who has a contract at Old Trafford until the summer of 2022.
According to Bild, Chong has already left the United camp as he nears a switch to Bremen, with the Bundesliga side expected to take the youngster on loan for the entirety of the 2020-21 campaign.
The Dutchman, who arrived at Old Trafford from Feyenoord's academy in July 2016, has operated as both a right-sided and left-sided attacker for Ole Gunnar Solskjaer's side this term.
United are currently preparing for their Europa League semi-final against Sevilla on Sunday night.