Liverpool and Barcelona have arguably the best attacks in world football right now, but it might instead be their defences who decide the Champions League semi-final.

Virgil van Dijk has improved Liverpool to the extent that he pipped Raheem Sterling of Manchester City to be named the Professional Footballers' Association (PFA) Player of the Year on Sunday, despite defenders rarely winning individual awards.

The Netherlands international has fully justified Liverpool making him the most expensive defender in football history by splashing out £75million to sign him from Southampton.

But Barcelona have a rock of their own at the back, with Gerard Pique enjoying one of his best seasons yet for the Catalan giants, who are hoping to win the treble once more.

Omnisport assesses their Opta numbers for the 2018-19 season so far to see if Van Dijk can truly be judged alongside Pique among Europe's elite defenders.

BUILDING FROM THE BACK

Both Liverpool and Barcelona play the ball out from defence, with Van Dijk and Pique charged with starting attacks. The Opta numbers show both players excel in this area, although Pique perhaps has the edge. In LaLiga this season, Pique's passing accuracy stands at a top-class 91.58 per cent, while Van Dijk's is 89.5 per cent in the Premier League. Van Dijk's passing accuracy of 87.67 per cent in the Champions League is also lower than Pique's at 89.21 per cent.

Van Dijk loses possession far more than Pique, giving the ball away 315 times in the league to Pique's 218, although he has made three more appearances and arguably tries riskier passes than the Barcelona defender. Their Champions League possession statistics are remarkably similar. With each player playing the full 90 minutes in nine matches in the competition this term, Pique has completed 529 passes compared to 526 for Van Dijk.

Both players have also recorded nine goal contributions this term, with Pique scoring seven goals for Barcelona compared with the Liverpool man's tally of four. Van Dijk's four credited assists are double Pique's two, though.

THE DEFENSIVE BASICS

Pique and Van Dijk may be good on the ball and a threat in the opposition box, but they are both also excellent at the nuts and bolts of defending. Van Dijk has won 277 duels in his 45 Premier League and Champions League appearances, compared to 236 for Pique in his 47 games in all competitions for the champions of LaLiga.

Van Dijk is arguably better in the air than Pique, recording 125 headed clearances to Pique's 118, but the former Spain international has the edge with his 36 tackles won beating Van Dijk's 32. Pique, however, easily has Van Dijk beaten for recoveries with 261 in his 33 LaLiga games far exceeding the 185 made by Van Dijk in his 36 Premier League appearances.

The numbers perhaps do not show Van Dijk's stunning impact on the Liverpool defence as a whole, though, while Alisson's signing from Roma has also boosted Jurgen Klopp's side. Liverpool have kept a clean sheet in 19 of their 36 Premier League games this season, Van Dijk featuring in all of them, while Pique has helped Barcelona to 15 clean sheets out of 33 LaLiga matches.

Assessing the Opta numbers for both players shows Van Dijk is, overall, on par with Pique this term, with the pair arguably the best two centre-backs in the world at the moment.

But Van Dijk will have his hands full with Lionel Messi and Luis Suarez, while keeping track of Liverpool's fluid front three - Sadio Mane, Roberto Firmino and Mohamed Salah - will pose a unique challenge for Pique.