There's been some controversy in the build-up to Monday afternoon's World Cup opener between Sweden and South Korea.
Group F was blown wide open after Mexico beat Germany and both sides will now feel they have a strong chance of progressing to the knockout stages.
The Swedes have been trying to get the upper hand against South Korea using tactics which might be considered underhand.
Swedish coach Janne Andersson admitted that one of his scouts, Lasse Jacobsson, covertly watched South Korea in training.
"He heard about a practice session, he didn't understand that it was a closed session, he didn't understand and he watched from a distance," said Andersson, as per the BBC.
"It's very important we show respect to all our opponents in all circumstances. If someone could interpret it in another way we regret it.
"It's been made a mountain out of a molehill."
How South Korea are messing with Sweden
South Korean coach Shin Tae-yong acted quickly to ensure that Sweden were unable to gather useful information on his team.
He told reporters that he has made his players wear different numbered shirts in order to confuse the "Westerners" who may be spying on his team.
"We switched them around because we didn't want to show our opponents everything and to try and confuse them," said Tae-yong, as per the BBC.
"They might know a few of our players but it is very difficult for Westerners to distinguish between Asians and that's why we did that.
Well played, sir.
Tae-yong continued: "All coaches probably feel their opponents are always spying on them.
"I think it's perfectly natural that we all try to get as much information on each other as we can."
South Korea will be hoping to massively improve on their 2014 World Cup experience, in which they managed to take just one point in the group stage.
But they will need big performances from Tottenham forward Son Heung-min and captain Ki Sung-yueng.
Will Sweden or South Korea make it out of the group? Let us know what you think by leaving a comment below.