Susaeta delighted with Spain call-up
The 24-year-old midfielder has played 233 games for his club but has never represented the national team.
He admits that he was surprised, but not bemused, at his inclusion for the friendly against Panama.
"I did not expect (Vicente) Del Bosque's call. In fact, I did not even know he was announcing a list today (Friday) and it has been a great surprise," Susaeta told Marca.
"It is a reward for years of hard work and sacrifice. It is a great honour for a football player.
"It has not even sunk in yet, but I am very happy about being able to join up with the national team."
The right-winger will be hoping to make his debut for Spain on Wednesday.