The time was a shirt number told you what position a player was, but now it doesn't mean a lot, so maybe it's time for a bit of imagination. Here're a couple to kick off. Cricketer Joe Root 66 Spurs player Harry Winks 40 Anymore for anymore?
If there is a player called Byfor, Buyfour, Byfour, or something like that he would have to be number 4