The 19-year-old goalkeeper collided with coach Uwe Kamps, resulting in the pair being rushed to hospital
The two collided when going for the same ball in training and the coach briefly lost consciousness, according to Bild.
Kamps' head was immediately wrapped up, while Ter Stegen held an ice pack to his face for some time until fitness coach Chris Weigl drove the pair to a local hospital.
Borussia Monchengladbach head coach Lucien Favre was optimistic over Ter Stegen's chances of facing Hamburg this weekend.
"It looked bad. With Marc, I hope that he can be there on Saturday in Hamburg."
Having made his Bundesliga debut in April, Ter Stegen has cemented his place in the Monchengladbach team, performing admirably in his side's impressive start to the season.