Hamburg forward Michael Gregoritsch sustained an ankle injury after clashing with teammate Ivo Ilicevic in training and is set to miss the match against Cologne on Sunday.
Gregoritsch, 21, was stretchered off the pitch after sustaining the injury when fouling Ilicevic, 29, during the session on Thursday.
Illicevic did not take kindly to the challenge, however, headbutting the Austria under-21 international shortly before he then received treatment to his ankle.
"They might have overstated their case," Hamburg coach Bruno Labbadia told reporters after the incident, "I'll talk to them both tomorrow, and put an end to this dispute."
Labbadia said he was unable to talk to both players on Thursday because Gregoritsch was taken to hospital.
"We will not play it down," the Hamburg boss said, but added: "We will not hang them from the gallow."
Bild, however, suggested that Illicevic might be suspended by the club on Friday.