Yan Valery is on standby to make his Premier League debut against Manchester United with Saints sweating over a left back injury crisis.

Ryan Bertrand is a major doubt to face the Red Devils, while Matt Targett also won’t be risked after suffering a head injury which forced him off at Leicester.

If Bertrand doesn’t make it then Cedric Soares is likely to switch to the left hand side, either as a full back or a wing back, with 19-year-old Valery, who performed admirably at the King Power Stadium, playing on the right.

Michael Obfamei, 18, is also in contention for a start after impressing Mark Hughes at Leicester.

Hughes said: “I am happy that we had the opportunity because you are never quite sure how young players will react to being given a start.

“It’s one thing coming on later in games when there is no expectation and no demand, you just try and make an impact which Michael has done in a couple of games.

“It wasn’t just a case of throwing kids in and hoping they are ready, I thought they deserved the chance because both of them are playing well in under-23 games and I felt it was the right time to introduce them and on the night they came through it with flying colours. If we need them at the weekend I have no qualms about putting them in again.

“The one thing you want from young players when you do introduce them is that they play with no fear, with energy, they play with enthusiasm and that can be picked up by the senior lads as well.

“I think that happened on Tuesday and the senior players really looked after the guys as well and were encouraged by the way they were playing.

“Nathan Redmond, who I pushed up front with Michael, was excellent in terms of being the senior partner in that pairing and looked after Michael and triggered each other off.

“It was really encouraging and certainly a good option for us.”

Saints are also having to prepare for another game without Danny Ings, who continues to nurse a hamstring injury.

The striker is expected to be fit for next week’s away double header at Tottenham and Cardiff, but Saints are remaining cautious with him to try and avoid an extended period on the sidelines. That means he is unlikely to be risked tomorrow.

“We are still missing Danny unfortunately,” confirmed Hughes.

“He hasn’t been on the grass yet. We hoped to get him back but it hasn’t been possible.

“He had a slight setback, nothing major but we are waiting to get him ready.

“We are hoping he will be back for next week and we are being careful with him so he comes back fit and sound for the games to the new year.

“Ryan Bertrand is struggling with an issue with his back which has flared up again.

“We have managed it in the past but it is causing anxiety at the moment and he hasn’t trained for a number of days.

“We are hopeful with a fair wind we might get him out but if not we are hopeful he will be back for next week.”