Claude Puel confident Jack Stephens can fill in for Virgil van Dijk
The England Under-21 international replaced Van Dijk during the second half of Southampton's 3-0 victory over Leicester on Sunday.
It was only the centre-back's sixth appearance for the Saints in all competitions.
Puel's side face the daunting task of travelling to Anfield tonight as they look to preserve their 1-0 lead from the first leg.
Virgil van Dijk picked up an ankle injury against Leicester
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When asked if the second leg at Anfield would be a good experience for Stephens, the Saints boss said: "If he has to play this game, I think he will play with good spirit and he's a good player.
"He is an England Under-21 international and he knows about these important games. He has the quality and I have full confidence with Jack.
"He's a good defender, he's intelligent, he can anticipate the action. Very good technically.
"With the Under-21s, you saw at home (against Italy at St Mary's), it was a good game, he was the best player on the entire pitch.
Jack Stephens has represented England at Under-21s level
"Since the beginning, it is a competition we have played with young players. For example, the last round against Arsenal away, we see the young players get a fantastic result.
"The focus was just on their game and this is just as important. They took confidence, they are upbeat in every training session.
"I think it is not a problem, but for Jack and all of the other players, it's just to think about the game, stay strong together."