Some decades ago, taking off your shirt to celebrate a goal was a norm and players could do that without being sanctioned for it. However, FIFA saw it as an ideal way to celebrate a goal so everything was good

In 2014, Diego Forlan abused this way of celebration which changed the whole thing. He scored a goal for Manchester United during a clash with Southampton and took off his shirt which was fair enough.

The jubilation lasted for long and when the game kicked off again he was still without his shirt. When Forlan resumed the game he was haring around, bare chested, in a bid to make a tackle.

This act didn't go well with FIFA as it spurred a lot of controversies and shortly after that FIFA had to imposed a rule to sanction any player who takes off his shirt during goal celebration which we are seeing now.

Here is the video celebration of Diego Forlan