Manchester United manager Jose Mourinho has confirmed that Romelu Lukaku and Marouane Fellaini are fit to face Derby County in the third round of the FA Cup on Friday (5 January) but will once again have to make do without Michael Carrick and Antonio Valencia, who is expected to be available for selection next week.

Lukaku suffered a nasty knock to the head during his side's 0-0 draw against Southampton and missed the win over his former side Everton on New Year's Day as Mourinho opted for caution over the well-being of his star striker.

Fellaini, whose season has been blighted by knee issues, has not featured for United since late November but could be afforded some much-needed minutes against Gary Rowett's Derby, a team Mourinho believes to have all the makings of a Premier League side.

"Romelu is back," Mourinho said in his press conference. "It was not a concussion; it was a precaution, a protection for him. He wanted to play against Everton, but this time he is back."

Mourinho also confirmed that full-back Valencia and veteran midfielder Carrick are closing in on returns to fitness. Valencia suffered a hamstring injury against West Bromwich Albion last month but should be fine to face Stoke City next weekend, while Carrick has returned to first-team training after undergoing minor heart surgery.

"From the injured players, Fellaini is back," Mourinho said. "And Michael Carrick is back to training, not to competition, but is back to training with the team. Antonio Valencia is not playing tomorrow but will be back to the team next week. So the situation is improving for us."

United will make a few changes to the side that secured a comfortable victory over Everton on Monday, with Sergio Romero primed to deputise for David de Gea between the sticks. The clash with Derby will be Romero's sixth start of the season for United, but the Argentina international is reportedly looking to leave Old Trafford in order to secure his place in Jorge Sampaoli's 23-man squad for the World Cup in Russia this summer.

Romero's departure would mean United would have to search for another understudy to De Gea but Mourinho hinted at his reluctance to let the former Sampdoria stopper leave this month and was keen to stress the importance of the 30-year-old in his first-team squad despite not affording him a minute of Premier League action all season.

"He is a top goalkeeper, he deserves to play and David deserves a rest," Mourinho said. "And Romero's going to be Argentina goalkeeper in the World Cup in a few months so for all what Romero means to us, Romero plays and I am going to play what I consider to be a very strong team."

Marouane Fellaini and Romelu Lukaku
Lukaku missed the clash against Everton with a head injury while Fellaini has been out for a number of weeks with a knee problem Getty Images