The Swedish champions sign Danish midfielder Mads Enggård, 22, from Norwegian club Molde FK.
"With Mads we get the type of player we have been missing since Malachowski left. We believe and hope that Mads can add a new dimension to the team once he gets used to the new surroundings," sports director Hans Larsson says on Mjällby's website.
The contract runs until 2030.
Enggård has recently been on loan at Vejle in Denmark.
