Manchester United manager Jose Mourinho is none the wiser over the length of time he will be without midfielder Paul Pogba, who remains out with a hamstring injury. The France international is expected to miss a fourth game in a row when the Premier League's joint-leaders travel to Southampton on Saturday (23 September), but there is increasing uncertainty over his future.

Reports suggest the 20-time English league champions have told Pogba to go on holiday to help speed up his recovery from an injury he suffered against Basel in the Champions League. Initial reports have suggested the 24-year-old could miss between four and six weeks of action, an absence that would rule him out until November.

Mourinho has continually dodged questions regarding Pogba's future availability – presumably to ensure any setback in his recovery is not noticed – and his stance remains no different as United prepare to travel to St Mary's. The two-time Champions League winner has re-iterated that Pogba's absence opens the door for the likes of Ander Herrera, Marouane Fellaini and Michael Carrick to make an impression.

"I have no idea," Mourinho said, according to United's official website. "No idea. But, again, it's a great opportunity for other players to play and I trust them all, so I'm not going to cry or be counting the days until Pogba comes back, not at all. When he comes back, welcome, but until then, I trust my people."

United made nine changes for the Carabao Cup thrashing over Championship side Burton Albion, with the likes of David de Gea, Antonio Valencia, Eric Bailly and Nemanja Matic left out of the matchday squad entirely. Mourinho is expected to recall the quartet, as well as Henrikh Mkhitaryan and Romelu Lukaku, who were unused substitutes for the third round tie. Marcos Rojo will miss out as he continues to recovery from a knee problem.

But of those players to start the game at Old Trafford, Anthony Martial stands the best chance of being retained after he took his goal tally for the season to four in just three starts in all competitions; a far cry from last season when he was largely sidelined by Mourinho. The ex-Monaco forward has started just one of the club's five Premier League games but could be in line to start on the south coast after an improvement in his attitude.

"I see a great improvement in the person, in the moods, in the face and body language," added Mourinho. "If we want a word: happiness. He is a happy guy. He is working extremely well, he starts matches and tries to do well.

"He goes from the bench, even if for ten minutes like in the last match at home, he tries to enjoy and to give something in the extra minutes. I am very pleased with his attitude overall, and then it is easier to play well."

Paul Pogba
Pogba has missed United's last two games with a hamstring problem.Getty Images