Van Dijk has returned to action after he was sidelined for the majority of the previous campaign with an ACL injury. He has already played 38 games in all competitions this season, totalling over 3,000 minutes for the Reds, and is seemingly back to his best.
But fellow Dutchman Stam says the 30-year-old is still getting back to his 'old level' and names other defenders, including Liverpool team-mate Joel Matip, that could also be regarded as the best in the world.
It's always difficult to say if he's the best," the 49-year-old told bettingexpert. "At the moment he is still coming back from his injury and he's getting back to his old level. He's showing his quality once again. Also because the team is performing very well it helps.
"They are winning games and that's very positive. There's still other players in the world who are very good defenders as well. In Italy, we've got a Dutch defender (Stefan) de Vrij at Inter Milan. I think they called him the best defender in Italy last year, so clearly he's also doing very well for them.
“I think if we keep it within the Dutch team, (Matthijs) de Ligt at Juventus is very young and I think he has a lot to learn, but he's a very good player. Outside of the Dutch, there is still (Sergio) Ramos, although he didn't play a lot, of course, but he is still, when fit, one of the best.
"I think (Joel) Matip who's playing next to Van Dijk is a very good player as well. I probably forgot quite a few, because it's not only the English league, it's also the Spanish league who've got very, very good players, of course."
When asked whether Van Dijk has any weaknesses, Stam suggested he could 'improve his positioning' and that the quality of the team around him means these things 'don't get punished'.
He continued: “If you look at the game now, most of the time, he's doing very well. It's not a weakness, but I think, at times, in his positioning is something he can improve on a little. But if you play in a team with a lot of quality sometimes these things, because you're still winning, don't get punished straight away.
“If you want to talk about certain things about him, and it's not about looking for weaknesses because I think in general he's doing very well, but these are things that you still, at times, need to be a little bit aware of. I don't know Virgil very well personally, but if you look at him, and if you hear him speak and if you see him on a pitch, then you can see that he's a clever guy and he's probably always analysing his own game as well and what he needs to do to improve."