Liverpool stars Mohamed Salah and Sadio Mane will face the ultimate test of their friendship and club comradeship when they go head-to-head to become kings of Africa.
Much has been said of the Reds duo's friendly rivalry and, although both have denied it, their club will hope Sunday's Africa Cup of Nations final doesn't go the same way as another infamous clash between two teammates at a major tournament.
As far as incidents of club teammates falling out at international level go, they don't get much more infamous than the 2006 World Cup quarter-finals.
Wayne Rooney was approaching the peak of his powers for England and Manchester United, and the Three Lions' 'Golden Generation' had been ushered in for the tournament in Germany.
Unfortunately for Rooney, though, United teammate Cristiano Ronaldo had other ideas.
Meeting in the World Cup last-eight, both with big aspirations of winning the trophy, what was expected to be Rooney's breakout tournament instead ended in ignominy.
Best mates in Manchester with Ronaldo at the time, their friendship was on display pre-game when Ronaldo gave Rooney a jokey headbutt nudge, but later things crossed over the line.
A tangle with Ricardo Carvalho just after the hour mark saw Rooney's boot end up in the Chelsea defender's groin, and Ronaldo burst onto the scene to protest at the referee.
Rooney was stunned to see his United teammate fly in and call for a red card, shoving him out of the way, but the job was done, Rooney was sent off.
An iconic wink to the bench showed Ronaldo knew exactly what he was doing, and helped earn his side a semi-final berth after knocking out 10-man England on penalties.
Ronaldo was well aware that a volatile Rooney could easily be provoked, and that will be the case for Egypt's Salah when he meets Liverpool teammate and Senegal star Mane in Sunday's AFCON final.
Mane has often been targeted by opposition players clearly in search of getting the Reds flyer sent off. In fact, iIn three out of four meetings between Liverpool and Atletico Madrid over the past two seasons, Jurgen Klopp has withdrawn Mane early with a booking to his name.
“It is obviously a part of football that I don't like,” Klopp said after facing Atleti in February 2020.
“The plan tonight [from Atletico] was to get Sadio out of the game with a second yellow card.
“I was afraid that Sadio's opponent would go down if he took a deep breath on him or something.
“I don't want to have this situation and that is why I took him off.”
Klopp even nearly came to blows with Arsenal boss Mikel Arteta earlier this season when the Gunners tried to send the sometime combustible Mane for an early bath.
Like Ronaldo, Salah will be all too aware Mane can be provoked, having faced his wrath during Liverpool's 2019/20 title-winning season.
Into the Burnley box during an October fixture at Turf Moor, Salah had two defenders around him and Mane open in space to slot home.
But with the No.10 just flirting with an offside position, Salah opted to cut back onto his right boot for a shot, which was easily blocked.
So angry at the decision, Mane had to be substituted, and fumed at Klopp's lookalike assistant Andreas Kornmayer, with James Milner and Joe Gomez forcing the irate forward to stay seated on the bench.
A scene in the tunnel showed just how awkward things had gotten, with Roberto Firmino in between the two gifting the audience with a look to the camera reminiscent of a scene from The Office.
The pair have been integral in taking Liverpool back to the top of the game under Klopp, and are clearly close friends, taking part in a 'Bezzies' feature for Liverpool in 2018, where the Africans were quizzed on their status as best mates in the Reds squad.
But, despite things clearly simmering down after the Turf Moor bust-up, the stakes couldn't possibly be higher as Senegal look to win their first ever AFCON, with Salah's Egypt in the way.
The duos' friendship would suggest things will stay calm, but the same could have been said for Ronaldo and Rooney, meaning Liverpool fans would be well advised to keep an eye out for any pre-game headbutts.
