While Ghanaian Anthony Annan is expected to start, Karimi will be among the substitutes.
Further new arrivals Angelos Charisteas and Danilo Avelar are not in the roster.
Meanwhile Magath received heavy criticism from Schalke fans and local media for his numerous transfers since taking over Schalke in summer 2009 but also specifically for the signings of veteran free agents Karimi and Charisteas.
Borussia Dortmund are sovereign Bundesliga leaders, Schalke only stand in ninth position of the table, 25 point behind Dortmund.