The Reds currently sit top of the Premier League table.
Aldridge told the Liverpool Echo: "For me, Van Dijk has been Liverpool’s player of the season so far. He looks fit, is right on top of his game, and I do think he has improved further having been handed the captaincy.
"If he wants another contract then the club will surely give it to him if he keeps up this kind of form. He is doing his case no harm at all.
"Maybe some people have taken Van Dijk for granted given they know how good he is, but I can assure you that ex-players such as myself don’t do that. We know how much of an influence he has on the squad and the work he has to put in to maintain his high level.
"Van Dijk struggled at times after his serious injury, but he is currently rolling back the years and playing like he’s a 25-year-old. Long may it continue."