Bayern star Muller caught telling ref Oliver: Atletico are the biggest bullies in world football!

Bayern Munich star Thomas Muller gave German-speaking audiences something to laugh about in Wednesday's 4-0 victory over Atletico Madrid as the forward was heard referring to the Spanish side as “the biggest bullies in world football” after receiving a yellow card.

The Champions League holders got their group-stage campaign off to a superb start at the Allianz Arena, with goals from Leon Goretzka and Corentin Tolisso bookended by a pair of strikes from Kingsley Coman as the hosts ran riot in Bavaria.

And while Muller failed to make it onto the scoresheet, the World Cup winner still managed to make headlines after the match due to his reaction to being cautioned by referee Michael Oliver after a perceived heavy challenge on Kieran Trippier in the first half.

With no fans present to drown out the shouts of the players on the pitch, Muller could be heard saying: “What's going on here? Hey! You can't be serious – we're playing against Atletico Madrid, the biggest bullies in world football! And I get a yellow for something like that?”

Despite not finding the net on the night, Bayern boss Hansi Flick was still quick to praise Muller after the game, insisting that the 31-year-old continues to be an integral part of what makes the German champions tick.

“He always knows where to be – and he coaches the team,” Flick told Sky following the victory. “He played on the right side today but he's still very, very important at the centre of our game. You could say that he's our coach on the pitch.

“Sometimes he could play a safer ball, sometimes there is a little too much risk involved. But that's what makes him who he is.”

Being such an influential character on the field, there have been calls for Joachim Low to recall Muller to the Germany set-up, with Die Mannschaft having claimed only one win in their previous five matches.

And Muller, ever the optimist, has left the door open for a return to international action when Germany take to the field in the European Championship in 2021.

“Hopefully the competition will take place next year,” Muller said to ZDF. “Everyone can see that I am in good shape – we don't need to say anything else about it. Let everybody just take it easy and then we'll see what happens.”