The origins of the right hamstring strain date back to the USMNT's 4-0 Concacaf Nations League victory over Cuba last month, in which Sargent scored twice. But the issue wasn't exacerbated until he came off the bench in Bremen's 3-2 road victory over his USMNT colleague John Brooks' Wolfsburg on Sunday.
"It’s a small, deep-seated muscle, so it’s only under very specific stress that the problem shows itself," said Bremen head coach Florian Kohfeldt in a club release. "That’s why he was able to play in matches and train so much without any problems. We’ll give Josh the time he needs for the injury to heal. He’ll be back in training at the start of January."
Sargent will miss Bremen's final four games of the calendar year, including their high-profile trip to Bayern Munich on Dec. 14.
The 19-year-old St. Louis native has scored two goals and two assists for the Bundesliga side in 11 league appearances (six starts) this season. He's netted three times in six appearances for the USMNT.