I'd point out what someone else already did - many professional sports leagues are either requiring or encouraging their players to get the shot.
If you were talking about a kid playing a game of soccer in the local neighborhood, you might have a point. That he is a professional player makes it much more likely that he received the jab than he didn't.
And do you really think second division Guatemalan football clubs require vaccination when less than a third of the country is vaccinated?
I honestly don't know but the odds seem vanishingly small.