Arsene Wenger expects Alexis Sanchez to be available for the FA Cup final but fears the Arsenal forward could miss the start of next season.
Wenger says an agreement exists to stop Chile calling up Sanchez early for the Copa America, which they are hosting.
Sanchez is free to face Aston Villa at Wembley on 30 May but success for Chile in the tournament - which runs until 4 July - would have a knock-on effect.
"If they go very far, he will miss the start of the season," said Wenger.
Sanchez, 26, has been one of Arsenal's most consistent performers this season, scoring 18 times since a £32m move from Barcelona after the 2014 World Cup.
The Copa America begins on 11 June while the 2015-16 Premier League season starts on 8 August.