Liverpool could welcome back key trio ahead of Europa League clash with Atalanta

All three have been sidelined by injury since February but have returned to training and look set to contribute to Liverpool's push for silverware over the closing weeks of the season.

Teenage midfielder Stefan Bajcetic, who has been out since September, is also back in training but is likely to have to wait a little longer for a first-team return.

"Obviously we didn't rush it with the boys," said Klopp. "That means they did a lot of training by themselves. Diogo and Trent worked as a group since two, three weeks and could do really proper training. It was very good yesterday.

"Stefan is different a little bit because he was out for much longer but is now training with us for longer as well. I think after the long spell he had without playing football it makes sense that we might give him a game in the under-21s and then let's see how he deals with that.

"That's not the plan with the other three guys. They are now back in training and now we have to see how we involve them, how we use them. That we need them is clear, but we need them in the best possible shape and we want to give them a kind of rhythm.

"It's always a challenge to reintegrate the guys but, with the quality they have, obviously it should be a bit easier and we will use them in the next days and weeks. What it means for tomorrow, I didn't make a decision yet."

Liverpool's injury problems have led to increased opportunities for their young players, many of whom have advanced their causes for further inclusion.

Klopp welcomed the availability of a bigger squad at a very busy time of the season, but he could be getting a knock on the door from 21-year-old midfielder Harvey Elliott if he does not get chances in the starting line-up.

"I want to be the player walking out, rather than coming on," said Elliott. "That doesn't mean I'm not grateful for coming on the pitch, I'm very grateful for every opportunity that I get in a Liverpool shirt, but for me it's about kicking on for myself and cementing my spot in the team.

"I'm not a kid any more, I'm a man, I'm growing up quickly, I feel like I need to take responsibilities into my own hands. If that means knocking on the gaffer's door, it's going to have to happen. But, at the same time, I do need to wait for my opportunities, I do need to be patient."

Atalanta sit sixth in the Serie A table and put out Sporting Lisbon in the previous round but have won only two of their last nine matches.

Pep Guardiola described playing the Bergamo-based side as like going to the dentist in 2019, and long-serving manager Gian Piero Gasperini remains in charge.

"There are now only great teams left in the competition," said Klopp. "It's really outstanding and we know what Atalanta are all about.

"Gasperini is doing an incredible job there for years and years and it's difficult to play against Italian teams, always was. Tactically they're super disciplined and super dangerous in a lot of areas, so we have to be at our best to get into the next round over these two legs."

There will be no flags on the Kop on Thursday night as fans stage a protest against ticket price increases next season.

Klopp admitted to mixed feelings on the issue, saying: "I understand the concerns and the discussion definitely. It's a tricky one from my point of view obviously to say.

"We want to have the people in the stadium, we want to make it available for everybody. There's a lot of good things the club is doing, but I understand 100 per cent where the supporters are coming from and I'm pretty sure they will find a solution.

"What we should make sure is that nothing gets between us and the supporters."