Liverpool defender Joel Matip has gone to a local hospital for tests on a shoulder problem, Sky Sports News understands.
Matip was involved in a collision in the final seconds of Liverpool's 1-0 win over Napoli in the Champions League on Tuesday, a victory with saw Jurgen Klopp's side reach the last 16.
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Meanwhile, right-back Trent Alexander-Arnold was replaced in the 90th minute by Dejan Lovren after sustaining a knock in the match at Anfield.
Klopp confirmed Alexander-Arnold will require further assessment for the injury ahead of Liverpool's match at home to Manchester United on Sunday, live on Sky Sports.
Liverpool's club website said Klopp is confident the issue is not serious, likewise with James Milner, who went off in the 85th minute with cramp.
"Trent got a knock on his foot, we are not sure about what exactly it is. It is painful," Klopp told reporters after the match.
"Millie [Milner] had cramps - I hope it was only cramp. That was it, I don't know anything else."
Liverpool finished second in Group C behind Paris Saint-Germain, who won 4-1 against Red Star Belgrade.
Both Liverpool and PSG will now look forward to the last-16 draw on December 17.