Liverpool are down to two fit centre-backs for tomorrow’s clash with Watford after Dejan Lovren was ruled out with a hamstring problem.

The Croatia international, who had suffered what was believed to be cramp in last weekend's win at Bournemouth, was forced off in Tuesday's Champions League victory over Red Ball Salzburg and left the stadium limping.

Asked about Lovren’s availability ahead of the visit of the Hornets, manager Jurgen Klopp said: "Out. He has a muscle injury, worse than last time. No time-frame. He's out."

With Joel Matip still probably at least two weeks away from a return from a knee injury it leaves just Virgil Van Dijk and Joe Gomez as his two fit central defenders.

"It's a concern. At the moment we have two and we need to take care of them and wrap them in cotton wool and ask how they want to train," added Klopp, who has signed an improved deal to keep him at Anfield until 2024.

"We have the kids too - Ki-Jana (Hoever) and Sepp (Van Den Berg). We have 'defensively minded' midfielders where we can use different systems. I have a lot of ideas but I hope to not have to use them."