Manchester United midfielder Paul Pogba is in contention to play in the first leg of his side’s last-16 Champions League tie at Sevilla.
Pogba missed the 2-0 FA Cup win over Huddersfield Town on Saturday because an illness, but trained on Tuesday.
Striker Zlatan Ibrahimovic, who has not played since 26 December because of a knee injury, has also returned to training but is not expected to play.
Marcos Rojo, Phil Jones and Marouane Fellaini are also likely to miss out.
Talking about Pogba, Mourinho said: “When a player is in a competitive (training) session it is normally because they are ready without problems.”
The injuries to defenders Rojo and Jones mean the return to fitness of Eric Bailly is timely after he played as a late substitute at Huddersfield.
Goalkeeper David de Gea is set to return after being rested for the Huddersfield game, while Marcus Rashford, Ander Herrera and Antonio Valencia also have a chance of recovering from injury to play in Spain, with all three joining in training.
Rashford and Herrera have missed the last couple of games and Valencia played in the Premier League defeat at Newcastle but missed out at Huddersfield.
United are second in the Premier League, 16 points behind leaders Manchester City, while Sevilla are fifth in La Liga, 23 points adrift of table toppers Barcelona.
Meanwhile, Roma manager Eusebio di Francesco has praised the “sensational” form of winger Cengiz Under before his side’s Champions League last-16 first-leg tie against Shakhtar Donetsk on Wednesday.
The Turkey international has scored four goals in three league games before the tie in Ukraine, and Di Francesco is thrilled with his improvement.
“He’s really come on in leaps and bounds,” said Di Francesco.
“He’s been key for us but I prefer to focus on the team rather than individuals. We’re delighted to have him here and we’ll try to exploit his talent as best we can.
“It’s Roma who are going out there to play tomorrow, not Cengiz.”
Roma will make a late fitness check on vice-captain Alessandro Florenzi before the game at the Metalist Stadion, and are still without long-term absentee, right-back Rick Karsdorp.