As long as your selected player starts the match and takes the field, all bets involving that player will stand and be settled according to the official match result - even if they only play a short amount of time due to injury.
If your bet is a player prop bet (for example, tries, run metres, or tackles), it's settled on that player's final recorded statistics for the match. This means if they're taken off early due to injury and don't reach your selected number, the bet will settle as a loss based on the stats they recorded before leaving the field.
For more information, see the General Rules, Tickets & Wagers article and our Terms & Conditions.