Van Dijk is going to see a specialist to find out the severity of his injury.
The Netherlands defender, who has played in every league game this season, was replaced at the half time break.
It's not clear how long Van Dijk will be out for, but the injury appears worse than first thought.
The other centre-back options for the Reds are Matip and Konate.
The Reds will face Wolves in the third round of the FA Cup.
"Virgil felt a little bit of the muscle and said it is fine, and he is a very good judge of these kinds of things," said the manager after the defeat. I didn't want to put myself in harms way.
When I told them we don't take risks, they looked happy. He just felt the intensity.
Luis Diaz and Diogo Jota are both working their way back to fitness after serious injuries.
They will play their next two league games on the road, away to BRIGHTON and at home to CHELSEA.