Both Modric and Marcelo suffered injuries in Madrid's 2-1 win over Malaga back in January, with the pair consequently missing the 2-2 Copa del Rey draw with Celta and the 3-0 league win over Real Sociedad.
But Madrid have now announced Modric has shaken off the knock to his right abductor, while Marcelo's hamstring problem is behind him, too.
Gareth Bale and Dani Carvajal remain unavailable for now, however, as the Wales star and the right-back continue their recovery.
Bale has been out of action since suffering undergoing surgery on an ankle injury in November, while Carvajal is sidelined with a muscular problem.
Madrid will be gunning for revenge when they take on Celta on Sunday following their elimination from the Copa del Rey last month.