The 27-year-old snapped an Achilles tendon in a freak accident in training and has been advised to rest for four months.
Manager Derek McInnes told the Bristol Evening Post: "I am absolutely devastated by what has happened to Marvin and this is a major blow for him and the team.
"Marvin wanted to play a major part in keeping us up between now and the end of the season but will now have to sit it out.
"The injury came out of the blue. He was just running when he pulled up suddenly in a lot of pain.
"We had the medical staff look at him immediately to assess the injury and it is the worst possible outcome."

































