The Portuguese star kicked out in frustration following some playful banter with close friend Marcelo during a training session, launching the ball into the stadium.
The relationship between teammates is a special bond. In fact, it's often said to be the reason former players miss the game so much.
However, as much as the time spent together behind closed doors can strengthen that bond, it can also sometimes prove a little bit too much at times.
Just ask Cristiano Ronaldo, who kicked out in frustration following some playful banter with close friend Marcelo during a training session.