Jurgen Klopp says Virgil Van Dijk's recovery from serious injury is going "really well" despite the Liverpool boss revealing the defender's knee "does not look like a knee should".
Van Dijk suffered knee ligament damage in last month's Merseyside derby, sustaining the injury as a result of a forceful challenge from Jordan Pickford.
The Dutchman could ultimately miss the rest of the club season and even next year's delayed Euro 2020.
His absence will be felt by the Reds given how influential he has been since making a big-money move from Southampton - he was colossal last season as Liverpool ended a 30-year wait for a top-flight crown.
Van Dijk attempted more passes (3,255) than any other defender in the Premier League, while only two other defenders with more than 1,500 had a better completion rate than him (89.2 per cent).
On top of that, Trent Alexander-Arnold (3,664) was the sole defender to have more touches of the ball than Van Dijk (3,624), his 239 duels won were the joint-fifth-best among rearguard players and his 191 aerial wins was bettered by only James Tarkowski (199).
The 29-year-old underwent a successful operation at the end of October, with Klopp confirming he is progressing well.
Asked if he was in touch with Van Dijk, Klopp told a media conference: "Yes, of course we are in contact. Considering the circumstances, he's doing really well.
"His knee doesn't look good, to be honest. It doesn't look like a knee should look, but it looks good for a knee with that surgery and the time he had since the surgery.
"So, yes, of course we are in contact and he's doing well, that's true."
Klopp also revealed Alexander-Arnold and Xherdan Shaqiri are making progress in their recoveries from injury, but confirmed Tuesday's Champions League clash with Ajax will come too soon for them.
They will be joined on the sidelines by James Milner, who sustained a hamstring injury in the 1-1 draw with Brighton and Hove Albion at the weekend.
While Alexander-Arnold and Shaqiri are not ready for the game at Anfield, Klopp said there is an outside chance Naby Keita could return.
"They are all getting closer to being back, but not close enough for tomorrow, I think," he said. "With Naby we have to check there still, but with the other two, they will not be ready.
"Trent looks quite good, but nobody gave me the green light for tonight so he will not be in it [training]. He hasn't trained with the team and stuff like this.
"I saw him today on the pitch doing his rehab stuff outside, so that looks already good, but I cannot decide when this rehab stuff is finished. I take the players only in the moment when I get the green light and that didn't happen yet.
"But from my rather experienced eye from what I saw today, it will not be that long anymore with Trent."
Liverpool can secure their place in the last 16 if they avoid defeat against Ajax and they will be confirmed as Group D winners if they beat the Eredivisie side and Atalanta fail to overcome Midtjylland.