It’s one of the intriguing sub-plots of Liverpool’s Champions League opener at Napoli – the battle between Virgil van Dijk and Kalidou Koulibaly.
Both defenders, and their team-mates, are well-associated with each other by now.
The Serie A side won last season’s corresponding fixture at the Stadio Sao Paulo 1-0 before losing the reverse encounter at Anfield by the same scoreline.
That match will be best remembered by Alisson Becker’s superb late save from Arkadiusz Milik – after all, without it, Liverpool would not have gone on to win their sixth European Cup.
But the match was decided in the 34th minute when Mohamed Salah somehow managed to escape the imposing Koulibaly and score the kind of electrifying goal that has become his trademark.
It says everything about Salah’s supreme talent that he made a player of the Senegal defender’s ability look foolish.
But it does beg the question whether Liverpool’s own man-mountain, van Dijk, the favourite for this year’s Ballon d’Or, would ever be beaten like that.
It was a topic discussed by football scouting writers Josh Williams and David Alexander Hughes in the latest episode of the Analysing Anfield podcast.
“Koulibaly is one of the closest out there to van Dijk, in terms of having the complete game, but I think what sets van Dijk apart is that he is more cool-headed,” said Williams.
“In the second fixture between the sides last season, it came down to a big moment, and Salah got the better of Koulibaly in it.
“Koulibaly gets talked up, and he is a superb defender, and he’s got an absolute tonne of useful traits, but van Dijk is on a different level, although not by a great deal.
“I think van Dijk is just that bit more compete, that bit more mentally cool and composed, that allows him to address the situations in front of him.”
Josh’s colleague goes further in his assessment of the Dutchman.
“I think there’s a bigger gap that you suggested,” said David. “If you look at the data, Koulibaly is a fantastic player.
“But I think van Dijk, for the purpose you’ve said there, just has this aura about him now, and I’d still be confident Liverpool could force an error from him on Tuesday – maybe Salah’s quick feet again.
“But I’d be surprised if that happened to van Dijk.”