Former Premier League referee Mike Dean says he used to set himself mini-challenges during matches "as a laugh".
Appearing on Jamie Vardy's podcast, Dean said he would see how long he could go without blowing his whistle, or stay inside the centre circle.
"We used to say 'we'll kick off now. Right, see how long we can go without blowing a whistle'," Dean said.
"I've done that a few times in the Premier League, before VAR obviously - went 20, 25 minutes without blowing a whistle.
That's rather interesting. I wonder if he was indulging in one of his little mini games whilst being a part of the refereeing in both 9-nils we suffered.