Paris Saint-Germain duo Edinson Cavani and Neymar engaged in the early stages of a dressing room rivalry at the weekend when the pair got into an argument on the pitch on two occasions over who would take a penalty and a free-kick.
Neymar won the argument for the latter with the help of fellow Brazilian Dani Alves, but Cavani made sure he was the one to take the spot-kick, only to then miss it.
Had the Uruguayan, who scored 49 goals last season after finally being given the chance to emerge from Zlatan Ibrahimovic's shadow, converted from 12 yards, he might have won Neymar's respect. The fact that he didn't possibly damaged their relationship more.
As the PSG duo attempt to work out their differences, here's a look at six other pairs of team-mates who were also great rivals despite sharing the same dressing room...
Oliver Kahn & Jens Lehmann
Defenders, midfielders and strikers may compete for places in a team, but ultimately there is always space for more than one in any given line-up. That is not the case with goalkeepers and is what spurred on the rivalry between German stoppers Oliver Kahn and Jens Lehmann.
Between them, the pair won numerous major trophies and played on some of the biggest stages any footballer could hope for. Yet only one of them could wear Germany's #1 jersey.
Kahn had long held onto the spot, but it was infamously Lehmann who was given the nod ahead of the 2006 World Cup on home soil. That resulted in increasingly juvenile tit-for-tat exchanges in the media, with each too stubborn to recognise the other's achievements.
Robert Lewandowski & Jakub Blaszczykowski
Former Borussia Dortmund team-mates Robert 'Lewa' Lewandowski and Jakub 'Kuba' Blaszczykowski were also international colleagues with Poland. And it was with the national team that their bitter personal rivalry appears to have its roots.
Dislike may have been bubbling away underneath anyway, but the problem became public in 2015 when Kuba, Poland's captain, had to withdraw from selection as a result of injury, leaving Lewa to skipper the side in his place. Lewa then also remained captain.
The animosity that developed further from that moment even led Kuba to be left out of the national team even after returning to fitness, before being recalled in time for Euro 2016.
Lothar Matthaus & Stefan Effenberg
Two of the most important players in modern Bayern Munich history and often paired together in the same midfield for club and country, Lothar Matthaus and Stefan Effenberg were more 'best of enemies' than 'best of friends'.
Their rivalry made headlines when Effenberg included a chapter in his autobiography titled 'What Lothar Matthaus Knows About Football', which just comprised a blank page.
Each man also berated the other in the press from time to time, with Matthaus suggesting Bayern should get rid of Effenberg. As it was, Effenberg stayed longer and captained the club to Champions League glory in 2001, the one title that had always eluded age-less Matthaus.
Andrew Cole & Teddy Sheringham
There was no severe reason why Andrew Cole and Teddy Sheringham famously didn't get on during their time together at Manchester United in the late 1990s and early 2000s.
Several years before Sheringham joined United, Cole had felt snubbed by the Londoner when replacing him as a substitute for England and knew from that moment he didn't like him. So when Sheringham did make the switch to Old Trafford, it was accepted that they wouldn't get on.
Fortunately for fans, the internal feud never manifested on the pitch. Those years were some of United's most successful, including the 1999 treble and further Premier League title wins in 2000 and 20001, with Cole and Sheringham both huge contributors to each triumph.
Zlatan Ibrahimovic and Lionel Messi
It was the presence of Lionel Messi at Barcelona that prevented Zlatan Ibrahimovic from having the kind of impact he would have wanted to make at Camp Nou, as well as contributing to his early exit just a year after joining the club in a huge £60m deal.
Ibrahimovic recalled in his 2011 autobiography how coach Pep Guardiola changed the team's formation just to suit Messi, leaving Zlatan 'in the shadows'.
"The balls passed through Messi and I didn't get to play my game. All right, I can understand [Guardiola's] dilemma. Messi was the star. But I mean, come on! He couldn't change the team the whole team to suit one guy," the talismanic Swede commented.
Cristiano Ronaldo and Gareth Bale
When Gareth Bale joined Real Madrid in a world record £85m (€100m) deal in the summer of 2013, Los Blancos were reportedly keen to deny that the figure was more than £80m they had spent making Cristiano Ronaldo the most expensive player of all time four years earlier.
Ronaldo is known to have a delicate ego and Real were seemingly keen to prevent their superstar from feeling alienated by the rival of the newest Galactico.
Bale was supposed to take over Ronaldo's mantle in time and in the years since there have always been rumours of a supposed rivalry between the two bubbling away under the surface. Publicly, they have always tried to make an effort to come across as friends, though.
This article is brought to you by Kingsman: The Golden Circle, in cinemas this September. Check out the trailer below.