Jürgen Klopp has confirmed Liverpool are waiting to discover the extent of the ankle injury Philippe Coutinho sustained during Saturday's 2-0 victory over Sunderland.
The Brazil forward was stretchered from the field with just 34 minutes of the contest played after going down following a challenge with Didier Ndong.
Klopp admitted in his post-match press conference the Reds do not yet know how serious the issue is, with Coutinho set to undergo a scan on the problem.
The manager said: “We have to wait for the scan. What we know in this moment is it is something with the ankle and that’s it, so we all have to wait.
“He had pain, but pain gets better. In the first moment, it was obviously very painful but when I saw him at half-time, he said the pain was much better. We have to wait.
“If I have no idea what it is, how can I imagine how long it will be [out]? I am actually quite an optimistic guy – so I hope he can train tomorrow!”
LFCTV GO: Klopp's post-Sunderland press conference
Meanwhile, Klopp confirmed Roberto Firmino also sustained a knock which led to his late substitution, adding: “He is much better than Phil, but has pain in the calf.”
A calf problem was also the reason Liverpool were without Daniel Sturridge for the Anfield encounter, with the striker reporting tightness in the muscle.
Klopp explained: “He had a tight calf. He hasn’t trained for two days and I have no idea when he is back. It is not sure that he can train tomorrow, so he was out because of this injury.”