Something has to give when talismanic defender Virgil Van Dijk takes on prolific striker Romelu Lukaku in a genuine heavyweight clash as Liverpool host Chelsea in Saturday evening's Premier League encounter.
Here, the PA news agency examines whether Van Dijk will be the immovable object, or Lukaku the unstoppable force at Anfield.
Both men boast tactical minds among the finest in the current world game. To limit either to praise around their physical attributes would be to sell both hugely short.
Van Dijk's astute positioning means he bears the ultimate classy defender's trait – hardly ever needing to make an actual tackle. His poise on the ball and ability to initiate attacks, coupled with his knack of thwarting the best attacking threats around, make him the complete defender.
Lukaku exudes similar assets but in the striker's mould, setting up an intriguing battle between the pair. Belgium's all-time leading scorer takes up clever positions to link play, always mindful of involving his team-mates. The 28-year-old is perhaps most dangerous when on the turn and running at stretched defences, where he knows just when to push on and when to create for a colleague. His predatory finishing in and around the box make him the ultimate handful for a defender.
Power and pace
Van Dijk and Lukaku's game nous allows them to exploit their hard-honed physicality and speed.
The Holland centre-back is impressively fast for such a sizeable unit and he knows how to cope with powerful attackers. Van Dijk will be entirely unfazed by Lukaku's aggressive approach.
Lukaku, however, could look to drop deep to drag Van Dijk out of his comfort zone of the middle of defence. While Van Dijk is unlikely to fall for any tactical ploys, if Lukaku can occupy the Liverpool totem, Chelsea will look to exploit the space created for others.
Form and fitness
Van Dijk is back at the centre of the Liverpool team after 10 months out with a serious knee injury. The towering defender has quickly put those injury woes behind him, however, impressing in Liverpool's successive wins – and clean sheets – to start the new Premier League campaign in style.
Lukaku's transfer from Inter Milan meant he missed pre-season at Chelsea, but the powerful hitman has kept himself sharp. Lukaku found the net less than 15 minutes into a stunning second Chelsea debut, bullying Arsenal in the Blues' 2-0 win on Sunday.
With both men appearing sharp in body and mind, Sunday's Anfield clash harbours great promise.
In three Premier League encounters Van Dijk has the edge, shutting out Lukaku each time. But Chelsea's Belgium star has returned to Stamford Bridge and the English top flight as the full package.
Van Dijk's Southampton edged out Everton 1-0 in November 2016, while the Dutchman has come up against Lukaku twice in Liverpool colours. The Reds saw off Manchester United 3-1 in December 2018, then the two teams endured a goalless stalemate in February 2019.
No goals yet for Lukaku in straight tussles with Van Dijk, but a gritty contest each time nonetheless – with the best undoubtedly still to come between a top-class pair.