Rojo, meanwhile, is still recovering from the muscle injury that forced him off after just 19 minutes of the win over Reading at Old Trafford last Saturday.
Mourinho admitted that he could not be 100% sure of their fitness, but is hopeful of having the duo available for the visit of his side's arch-rivals.
"I think Rojo and Zlatan are available. I cannot confirm with 48 hours to the match but I think so," he told the club's official website.
Victory for United at Old Trafford would see them move just two points behind Liverpool, who currently sit second in the table.