Netherlands captain Van Dijk was taken off at halftime in the 3-1 Premier League defeat by Brentford at the start of January. He returned to Liverpool's bench for their 2-0 win over local rivals Everton on Monday.
When asked if Van Dijk is available to start against Newcastle, Klopp told reporters, "I think so. Yesterday he looked absolutely ready, and today I think he will look the same.
"And then we make a decision."
Liverpool are languishing in ninth place in the standings on 32 points after a season blighted by poor form and injuries.
Their opponents Newcastle, on the other hand, are fourth and fighting for a Champions League spot after a run of 17 league games without defeat. They have lost one game this season, a 2-1 defeat by Liverpool in August.
Klopp heaped praise on counterpart Eddie Howe for the "exceptional" turnaround he has overseen at St James' Park.
"This is a massive game. If you want to reach something this season, we have to chase everybody, especially those who are ahead of us in the table," Klopp said.
"It will never be easy, but we have to try. It'll be tough; Newcastle are the best defence in the league, lost just once to us, we needed a late goal. They are very consistent and that is the first step to success.
"Eddie Howe has done an exceptional job, absolutely exceptional. The financial possibilities they have, or will have, are exceptional, but it is not because of that. He arrived in a difficult situation, they stayed comfortably in the league, now the team is unrecognisable."
Klopp added that Thiago Alcantara and Luis Diaz are not available for the game, and that defender Calvin Ramsay is expected to miss the rest of the season after undergoing surgery on a knee injury.
