During Melsungen's European League match against on Tuesday evening, Mensing lost his footing after 12 minutes and fell to the floor holding the lower part of the right leg, clearly in pain.
Mensing received treatment on the floor field while both teammates and opponents looked on concerned. He was then followingly carried to the bench by teammates Rogério Moraes and Jonathan Svensson.
Melsungen are still to make a statement on the extent of the injury.
After the match it wasn't the defeat but instead Mensing's injury that was a cause of concern for Malsungen sports director Michael Allendorf.
"I don't care about the result. I would have preferred to accept a 20-goal defeat if we could have gone home without injured players. Aaron Mensing's injury is the next big shock for us after the other long absences."
"We expect a very serious diagnosis, but we have to wait for it until we return to Kassel", he said to the club's website.
Melsungen's head coach, Roberto Garcia Parrondo, was also affected by the injury to Mensing.
" We had no chance to win. Kiel was the better team. After Aaron's injury, everyone was shocked and we are in a difficult situation with six or seven injured players", he says.
MT Melsungen are currently leading the German Bundesliga after 21 games, one point ahead of Füchse Berlin.