The Spaniard has been sidelined since the 2-0 win at Burnley at the start of September but is back to boost Mourinho’s midfield options for the tie against the Championship outfit.
Nemanja Matic could also return after sitting out Saturday’s 1-1 draw with Wolverhampton Wanderers through suspension, but Marcus Rashford will have to serve the last of his three-game ban.
“Ander is ready,” Mourinho told MUTV on Monday.
“Marcos Rojo is the only player that is not available through injury and it’s Marcus Rashford’s last suspension match."
Mourinho confirmed before the game against Wolves that Diogo Dalot would feature against the Rams, having impressed on his debut in last week’s Champions League win over Young Boys.