The Argentina international has been out of action since February 18 with a persistent thigh injury which has seen him feature just once since the start of the calendar year.
He returned to training last week and has now made the squad again alongside Xabi Alonso, who missed the Champions League contest at APOEL in mid-week through suspension.
However, Di Maria is expected to start the match on the bench as Mourinho explained that the 24-year-old 'still cannot play for 90 minutes'.
Meanwhile, Sami Khedira, Ricardo Carvalho and Lassana Diarra have been ruled out of Saturday's game through injury, while Pepe will have to serve the second part of his two-game ban.
Madrid are at the top of the Liga standings, with 75 points from 29 matches, while Osasuna are sixth, with 43 points.
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