Valencia have confirmed Goncalo Guedes will miss Portugal's international matches this month due to a thigh injury.
The forward was substituted after just 12 minutes of Sunday's 1-1 LaLiga draw with champions Barcelona at Mestalla.
Tests have shown Guedes has sustained damage to his left adductor and Portugal have agreed to allow him to stay in Spain to begin treatment. Benfica midfielder Rafa has been called up as his replacement.
Fernando Santos' side face Poland in the Nations League on Thursday before a friendly match with Scotland at Hampden Park on Sunday.