Dani Alves was on the receiving end of a cheeky challenge from Luiz Felipe Scolari in training on Monday when the Brazil manager kicked the Barcelona star in the nuts at their Granja Comary base camp in Teresopolis.
The marauding full-back was enjoying a pleasant game of keepy-uppies on the touchline during a drinks break with team-mate David Luiz when the 65-year-old casually flicked out a boot and clipped Alves in his private parts.
Scolari nonchalantly departed the scene as if nothing had happened, leaving Alves rolling round on the floor while clutching his nether regions. Thankfully the incident was taken in good faith and it wasn't long before the defender was back on his feet and juggling the football again.
However, it will come as a warning to any potentially unruly Brazilian stars of what could happen if they get on the wrong side of their no-nonsense tactician known as 'Big Phil'.
Scolari's crotch kick on Alves is the latest in a series of unusual training ground episodes that have occurred within the Brazil camp, after poster boy Neymar was spotted karate kicking fellow striker Fred at the weekend.
Like Alves after Scolari's tackle, the Fluminense forward escaped unharmed and dusted himself off after a spate of laughter, but the same can't be said for fellow striker Hulk who limped out of training with a thigh problem on Sunday and remains a doubt for Brazil's second Group A game against Mexico on Tuesday. Bernard or Willian will be waiting in the wings if Hulk doesn't recover in time.
After recording a comfortable 3-1 victory over Croatia in the World Cup opener on Thursday - courtesy of two goals from Neymar and one from Oscar - Scolari's men know that victory will all but confirm their place in the knockout phase, with a potentially mouth-watering tie against holders Spain in the last 16.
And, while the atmosphere in the Brazil squad remains harmonious, it's easy to see why the host nation are one of the favourites to go all the way in the tournament. Alves would likely give his left nut now to guarantee they win it!
Watch footage of Luiz Felipe Scolari's cheeky nut challenge on Dani Alves in the video below - and share some of your other favourite World Cup moments in the comment box provided!