Martin Skrtel's return from injury has been set back by around "two or three weeks" after suffering a fresh problem in his recovery, Jürgen Klopp has explained as he gave an update on his squad's injury.
The Liverpool centre-back was forced off in the defeat at Watford on 20 December after he sustained a hamstring injury and has missed 12 games since.
But despite being pencilled in for a return to first-team training at Melwood this Saturday, Klopp will be unable to call upon the Slovakian's services for at least another couple of weeks.
And the Reds boss explained to the media that they have had a "problem" with Skrtel, who he said is "a little bit re-injured" and now "needs another two or three weeks [to recover]" but said they "have to see" when he will return to fitness.
That could mean the 31-year-old is touch-and-go for the second-leg of the Reds' Europa League Last 32 tie with FC Augsburg, whilst he will be desperate to get back in training prior to the Capital One Cup final against Manchester City on February 28.
Despite the defender's setback, Klopp had more positive news on attacking trio Philippe Coutinho, Divock Origi and Daniel Sturridge who are all making good progress in their respective recoveries.
Trio not in contention for Sunderland game
However, none of the three will be considered for this Saturday's Anfield clash with Sunderland in the Barclays Premier League - though they may be assessed for Tuesday's fourth round FA Cup replay at West Ham United.
Klopp added that Sturridge is "back in training" and has been for the last two days, which he called "great." He explained that "everything looks good in this moment" for the striker, saying he is in "normal football training" which is "really good" for the club and "good for him."
He revealed that on Wednesday, he was "together with Phil [Coutinho] and Divock [Origi]" and said: "If you see these three players then you know what you have missed for a few weeks."
"With Divock, Phil and Daniel in training, of course you think after five minutes that maybe we should take them back into the squad," added the German, who said that is the moment you have to say be patient and realise there are "another three sessions which we can use."
Klopp suggested that if they can make it through the sessions between now and Tuesday's trip to London to take on the Hammers, then "they are available" for the game and said in this moment, "that's the idea" provided "nothing happens in the next session."