Anybody know what happens to a 3rd round matchup bet if a player withdraws ?
Check the rules at the Sportsbook where you placed your wager. Each have their specific rule for withdraws in round match-ups.
For example some will say something like this:
"Both players must tee off and complete two holes for wagers to have action."
And some will say just one hole, or 5 holes or nine holes, or whatever. It all depends on the particular Sportsbook.
For the most part if the player you bet on withdraws during play, you lose. If he/she withdraws before the round starts, the bet is voided.