It was after more than an hour that Jansson sat down on the pitch and broke off the 0–0 meeting with AIK at home.
After an examination on Friday, it is clear that the 34-year-old will be away from play for the spring, writes MFF on its website.
He will thus also miss the final in the Swedish Cup on Thursday when Häcken comes to the stadium in Malmö.
Two Allsvenskan matches remain for MFF during the spring – IFK Göteborg away on Sunday and Häcken at home on June 1 – before a summer break awaits.
The reigning champion team is fifth on 19 points – seven behind series leader Mjällby, who awaits in the Allsvenskan restart on June 30.
MFF also announces that striker Erik Botheim has now operated on the fracture in his lower leg that the Norwegian sustained in mid-May. How long Botheim will be away is not clear.
