But he won't let anyone know how!
Babel joined the Cottagers on loan in January and hopes he can fare better against Van Dijk than the rest of the Premier League.
"He does have a weakness. I don't want to say what it is," Babel told The Times.
"I don't think in the Premier League anyone has made that aware yet."
Former Reds forward Babel went on to hail international colleague Van Dijk, and believes he even has another gear to go into.
"I think he can get better by 30 per cent. I still feel he plays on 70 per cent. He can do much more. He can be fast if he wants," Babel added.