If the boot is on the other foot, a situation is the opposite of what it was before, so that the people who were previously in a better position are now in a worse one, and those who were in a worse position are now in a better one. Comments like that from a manager are better made in private. If the boot was on the other foot and a player went public like that after a game, his club would quickly be looking to punish him. The fact is, I'm in the job. You may have assisted along the way, but as far as I know you're not in a position to remove me. The boot is now on the other foot. Note: Until the end of the 18th century, shoes could be worn on either foot, as cobblers did not make `right' and `left' shoes. If a person found that one of their shoes hurt their foot, they could try wearing it on their other foot to see if it felt better that way.