The 25-year-old had to be helped from the pitch in the 14th minute of HSV's 1-1 draw with 1. FC Nuremberg after being treated on the pitch having fallen awkwardly following an aerial challenge.
Double ligament tear
The diagnosis of a double ligament tear was confirmed after the defender underwent a more thorough examination. As a result head coach Thorsten Fink will be without Mancienne, who has established himself as a first-team regular this season, for four to six weeks.