NewsLFC fitness update: Klopp on Van Dijk, Diaz, Konate and Thiago
The defender was an unused substitute for Monday night's Merseyside derby victory over Everton, having taken a spot in the matchday squad for the first time since the start of January after recovering from injury.
But Luis Diaz, Ibrahima Konate, Thiago Alcantara and Calvin Ramsay remain sidelined for the Reds.
Asked on Friday whether Van Dijk was fit to start at St. James' Park, Klopp told reporters: "I think so.
"Yesterday he looked absolutely ready. I think today he will look the same and then we make a decision."
Klopp continued: "Same squad, nothing happened. Who could have come back since then? Ibou not yet, Luis not yet but that's it pretty much.
"Nothing happened on the injury side. Thiago, not available. Calvin had surgery, not available. But that's it."
AcademyU18s match report: Comeback at Birmingham sends Liverpool to PL Cup quarter-finals
MatchThe opposition lowdown: Southampton
Interview'We can't take our foot off the gas' - Caoimhin Kelleher previews Southampton v Liverpool
Play nowCaoimhin Kelleher birthday quiz: Can you get 9/9?
FeatureClinical Harvey, Robbo's 'bullet' and Danns shock - things spotted in Friday's training