Joe Gomez will make a long-awaited return for Liverpool on Sunday, with Jürgen Klopp admitting he resisted buying defensive cover to keep the first-team path clear for the England Under-21 player.

The 19-year-old has not played a senior game for Klopp having ruptured a cruciate ligament on England duty at the start of the manager’s tenure and suffered an achilles injury in pre-season. Following a carefully staged rehabilitation period and six games for the under-23s, however, he is in line to start Sunday’s FA Cup third-round tie against League Two side Plymouth Argyle at Anfield, where the visitors will be backed by more than 8,500 fans.

Liverpool have rejected several loan inquiries for Gomez, with Klopp confident the teenager, signed for £3.5m from Charlton Athletic in 2015, can have an influence at Anfield this season. And he admits Gomez’s potential was a reason for not signing more defenders during the teenager’s absence, with Liverpool offloading Martin Skrtel, Kolo Touré and Brad Smith during the summer and signing two central defenders in Joël Matip and Ragnar Klavan.

The Liverpool manager explained: “It depends on the quality of the player. If you bring a talent in too early you don’t help him. Joe, for sure, is one where it is worth keeping a space in the squad for him. He was really unlucky. I can still remember the situation when he had the injury. I saw it in an under-21 game on television and thought: ‘Oh my God’. It was really unlucky.

“Sometimes life should be nice, that the train is not running away without you, and that’s what we always thought about. Everybody was and is sure about his quality. He’s still a very, very young boy and we took him for a reason. OK, it was before I was here but it was a good reason. We try to create some space where he can develop and perform when possible.”

Gomez receives treatment after the cruciate ligament injury he suffered while playing for England’s Under-21 team against Kazakhstan in October 2015 Photograph: Joe Toth/BPI/REX Shutterstock

Klopp visited Gomez as soon as scan results confirmed the extent of the knee injury sustained against Kazakhstan 15 months ago. The Catford-born defender has admitted the manager’s encouragement and working alongside Danny Ings, who ruptured his cruciate in the same week, were important factors in his recovery. “The first time the manager spoke to me was the thing that stuck with me the most,’ Gomez said. “I had just come back from the scan and he was positive and told me to stay positive. He just told me not to stress about it. It was nice of him to take that time as I had just found out and it was an important moment.

“It wasn’t easy. The timing of it was frustrating, having a new manager come in and not being involved while watching the team doing so well, but I have had a lot of good people around me. Ingsy was with me most of the time and the medical team, Matt Konopinski, Jordan Andreas, everyone helped me. It wasn’t easy at the time but I got through it.”

The defender made seven appearances for Liverpool for Brendan Rodgers before injury struck and admits the extended spell on the sidelines, coupled with another serious knee injury for the unfortunate Ings, has brought a fresh perspective to his Anfield career.

“When you have experienced something like that you don’t take things for granted any more,” added Gomez, who impressed at left-back for Rodgers but prefers playing in central defence. “Just being able to play, and being here at this club, is a blessing in a way. You can get caught up in a lot of things playing for Liverpool but the main thing is to stay grounded. That’s something I won’t forget. I know it can get taken away from you in an instant with an injury like that.

“The key is to stay level-headed: don’t get too high with the highs and at the same time stay strong when things aren’t going your way. Just being healthy and having the opportunity to play isn’t something that everyone has all the time. I am lucky to be able to do something I enjoy doing. I still have a long way to go. I’m back but I’m not properly back yet. I am not in the team yet. There’s still a lot of hard work to be done but having been out for so long I am just really grateful to have this opportunity.”