Claude Puel has backed Jack Stephens to shine in the most difficult of circumstances.

The 23-year-old centre half was barely even on the fringes of the first team picture just a few months ago, but now looks set to start in Saints’ first League Cup final since 1979 as they take on Manchester United at Wembley tomorrow.

The sale of Jose Fonte and injury to Virgil van Dijk have allowed Stephens the chance to establish himself alongside Maya Yoshida and, with Martin Caceres not joining up with the team until just before their Spanish training camp, it looks likely the youngster signed from Plymouth in 2011 will get the nod.

Puel said: “For the moment I didn’t give the team as the start. We’ll see if Jack starts this game.

“But for me of course I’m confident all my confidence with the player, with the squad.

“I saw the training camp in Spain, very good concentration, very good spirit, quality in the training sessions.

“Big attention, for Jack, for all these young players.

“They stay calm and just focus about what they can have to do. It’s the most important for me and for the start, keep them in this good attitude and not just to think about speculation about a good result, bad result, we’ll see this. The most important is to play this game.”

Saints were unable to get a January deal for a centre half over the line, meaning they turned their attentions to Caceres after the window closed as he was a free agent.

However, his late link up with the squad, and the fact the former Juventus and Barcelona man hasn’t started a game for a year, is clearly an issue when it comes to throwing him in at Wembley for a debut.

Puel hinted his new man will most likely be a sub.

“I was surprised by his good physically fit, because he can come on the training camp in Spain with a good level, good quality,” admitted the Saints boss.

“He worked hard along with the fitness during his injury and I don’t know if he can participate at the beginning of this game but he can give good opportunities and solutions for us for the future.”

Puel will also today assess the fitness of Sofiane Boufal.

The Moroccan creative talent came off injured during the win over West Ham at the start of the month but was able to return to training on Thursday.

Puel is prepared to make a late call on Boufal’s availability for Wembley in the hope he can have one of his favoured attacking threats ready to play.