Jurgen Klopp says Liverpool will be without Nathaniel Clyne for "some time" due to his lingering back issue.
Clyne has not appeared at all for Liverpool this season as a result of his injury and was not named in the 25-man squad for the group stages of the Champions League.
However, Klopp has revealed that he hopes to register Clyne for the later stages of the Champions League, should Liverpool qualify.
"Nathaniel is working hard on his rehab and we have kept a close eye on his progress, but the reality is we are looking at some time still before he is back and available for selection," Klopp told the club's official website.
"I am told it will be longer than just a couple of weeks, so we will continue to monitor and assess.
"It is pretty certain he'll not be available for the majority of the Champions League group matches. If we are fortunate enough to still be in UEFA competition in the New Year he could be added to the squad then.
"The medical guys are pleased with how he is responding and Nathaniel has shown a really strong attitude, given he is not someone who is used to being out injured."
In Clyne's absence, youngsters Trent Alexander-Arnold and Joe Gomez have been deputising in the right full-back spot.
Klopp added: "What is positive for us is how Joe and Trent have stepped up and grasped their opportunities."