Liverpool manager Jurgen Klopp provided a promising update on Virgil van Dijk, but he remains unsure when the star defender will return for the Premier League champions.

Van Dijk underwent surgery on his knee in October after suffering a serious injury in the Merseyside derby against Everton.

The Netherlands international has been missed by Liverpool, who are fourth and six points adrift of rivals Manchester United ahead of hosting Burnley on Thursday.

Klopp was upbeat about Van Dijk's rehabilitation, but he is unsure when the 29-year-old might return.

"He looks really good," Klopp told a news conference.

"I spoke this morning to him on the phone, he is in a really good mood so it's all very promising but I don't know when he will be back.

"There are for sure a lot of stages still to go over or to pass, whatever, that's clear. I had this injury myself.

"For the time we are in and for how long he is out now, how long the rehabilitation is going on, he looks really, really promising."

Since Van Dijk's Premier League debut for Liverpool in January 2018, Klopp's men have won 72 of 95 games with him in their side.

That win percentage of 75.8 drops to 50 in the 14 league games in which Van Dijk has been absent.

Liverpool have also averaged more goals for (2.3 to 1.9) with Van Dijk, and also conceded more with him (0.8 to 0.6) than without him.

Klopp's side, however, have struggled for consistency so far this season and head into their clash against Burnley on a four-game winless run in the league.