Hey there!
For player prop bets, it depends on whether the player actually participates:
If the player doesn’t play at all, your bet is void and your stake is refunded.
If the player appears even briefly—a snap, serve, or minute of action depending on the sport—the bet stands and is settled based on their performance.
So if the player never plays, the bet is void and the stake may be refunded depending on the bet market. If the player retires mid-game after participating, the bet is valid and settled according to the outcome.