Liverpool's promising young defender, Giovanni Leoni, is set to face a lengthy spell on the sidelines after suffering a devastating knee injury during his debut for the club. The 18-year-old Italian, who joined Liverpool from Parma this summer for £26 million, sustained a torn anterior cruciate ligament (ACL) in his left knee during the Carabao Cup victory against Southampton on Tuesday.

The news was confirmed by Liverpool manager Arne Slot ahead of their Premier League match against Crystal Palace. Slot revealed that Leoni is expected to be out for approximately a year due to the severity of the injury. "He is not in a good place of course because he tore his ACL so he will be out for around a year," Slot stated.

Leoni's injury occurred in the 78th minute of the game against Southampton, after he had impressed in his first appearance for the Reds. He was stretchered off the field with his left knee strapped up. Sky Sports in Italy reported the initial diagnosis of a torn cruciate ligament.

The injury is a significant blow for both Leoni and Liverpool. Leoni had been looking forward to making his mark at the club after his summer transfer. "Being so young, coming to a new country, playing so well in your first game, it is very hard to take a positive - there is no positive, but he is still so young, has so many years to go after he recovers from a terrible injury like that," Slot commented.

Following the match, Leoni expressed his gratitude for the support he had received. "I want to sincerely thank every single person who has shown me support in this difficult moment," he wrote on Instagram. "It wasn't the debut I had always dreamed of, but I will give everything to be back playing in this magical stadium as soon as possible. Thank you so much!".

Teammates have rallied around Leoni, offering messages of support. Florian Wirtz wrote, "You'll come back stronger," while Alexander Isak responded with emojis. Virgil van Dijk also showed his support with emojis.

Leoni's injury leaves Liverpool with only three senior center-backs: Virgil van Dijk, Ibrahima Konate, and Joe Gomez. Slot has suggested that Wataru Endo and Ryan Gravenberch are capable of filling in at center-back if needed. Liverpool had attempted to sign Marc Guehi on transfer deadline day but were unsuccessful. Slot did not comment on whether the club would renew their interest in January.

With Leoni sidelined for an extended period, Liverpool are considering their options for their Champions League squad. Federico Chiesa, who provided both assists against Southampton, could be added to the squad as a replacement for Leoni. "We have looked into this,” Slot said. “I cannot tell you exactly where that process is at the moment. That is not something I do myself, there are other people doing this. If I am informed correctly, if a player has a longer than two-month injury you are allowed to replace him".

The club is focused on supporting Leoni through his recovery. The young defender faces a long road ahead, but he has pledged to return to the pitch as soon as possible.