If a Ryder Cup player gets injured and is unable to play in the crucial Sunday singles matches, the Ryder Cup "envelope rule" is enforced. This rule was introduced in 1979 and requires each team captain to submit a sealed envelope before the singles matches containing the name of one player who would sit out if an opposing player is injured and cannot play. Here's what happens under the envelope rule:
- If a player on one team is injured and cannot compete in the Sunday singles, the opposing captain's envelope is opened.
- The player named inside that envelope sits out the singles matches as well.
- The match between the two players (the injured player and the envelope player) is considered a tied match, and both teams receive half a point each for that match.
- If two injured players (one from each team) withdraw, both are paired together with a tied match, and the other players are re-paired for their matches.
- This rule only applies if the injury withdrawal happens 30 minutes or more before the singles match starts; if a player withdraws after that, their match might be forfeited.
This rule helps maintain a level playing field and avoid one side gaining an advantage due to injury-related absence in the singles stage where all 12 players are supposed to play. For example, in 2025, Viktor Hovland's injury triggered discussions about this rule possibly coming into effect.
