Ghana attacker Nana Ampomah faces a spell on the sidelines after picking up an injury during a German Cup game on Saturday.
The winger was forced off the pitch in the 62nd minute as the Flingeraner came from behind to snatch a 3-1 triumph over Villingen in the first round fixture.
His substitution came only six minutes after he scored to draw his club level in the match.
"There is a suspicion of a torn muscle in the adductor area of Nana Ampomah," the club announced on social media on Sunday.
"Our attacker will undergo further investigations on Monday.
"Fingers crossed that it is not so bad."
Saturday's match was Ampomah's competitive debut for Dusseldorf since completing a transfer from Belgian outfit Waasland-Beveren last month.
A confirmed injury will certainly rule him out of the Flingeraner's upcoming opening match in the German Bundesliga against Werder Bremen on Saturday.