Liverpool beat Napoli by the required scoreline on Tuesday night to progress to the knockout rounds in the Champions League, but it may have come at a cost after Trent Alexander-Arnold, James Milner and Joel Matip in sustained potential injury problems in the game.
All three players pulled up late on, with Alexander-Arnold and Milner replaced by Dejan Lovren and Fabinho respectively for the final few moments of Napoli pressure.
Delivering an update afterwards, manager Jurgen Klopp was hopeful that none were nursing serious problems as he hadn't, at that point, heard anything bad.
"Trent got a knock on his foot, we are not sure about what exactly it is. It is painful. Millie had cramps - I hope it was only cramp. That was it, I don't know anything else," the Liverpool boss said, via the club's official website. "Nobody told me anything about [Joel's] shoulder, so hopefully that’s a good sign."
Paul Joyce of The Times tweeted later on that Matip had been taken to hospital for tests.
Joel Matip has gone to hospital for tests on a shoulder injury— paul joyce (@_pauljoyce) December 11, 2018
As the Reds prepare to host fierce rivals Manchester United on Saturday, Klopp will be sweating on the fitness of Alexander-Arnold and Milner until more is known about their condition.
Both players would almost certainly start otherwise, with Milner experienced in years of big games. He has captained Liverpool against Tottenham and Arsenal so far this season and played 86 minutes of the credible away draw against Chelsea.
Liverpool moved to top of the Premier League following their win over Bournemouth last weekend, combined with Manchester City's shock defeat to Chelsea. A victory against a United side that has won fewer than half their 16 league fixture this season would see them stay there.
City, meanwhile, face Everton at the Etihad Stadium with David Silva and Kevin de Bruyne both ruled out and Sergio Aguero still considered a doubt.