The Chelsea striker was given time to recover after a frustrating time with injury.
Diego Costawas left out of theSpainsquad for the games with Costa Rica and Belarus because he is not in "top condition", according to coach Vicente del Bosque.
Chelsea striker Costa concluded a first season in England with a first-half penalty - his 20th in the Premier League - in the Blues' 3-1 defeat of Sunderland on Sunday but was given time to rest by Del Bosque with the striker plagued by niggling injuries in recent weeks.
He will therefore miss the home friendly with Costa Rica on June 10 and the European Championship qualifying trip to Belarus four days later.