Diego Costa has been overcome by nerves ahead of his debut for Spain.
The Brazilian-born striker, who is a naturalized Spanish citizen, says he is feeling anxious ahead of Wednesday's friendly against Italy at the Vicente Calderon Stadium, but there was also excitement to finally play for his adopted homeland.
Diego Costa says "I will just try to be myself. Playing for the national team is something else, a whole other world."
The Atlético Madrid striker was first selected to play for Spain in a couple of friendlies last November by national squad coach Vicente del Bosque, but got injured. Costa says his club teammates have helped comfort him, while his new teammates and coach have also been accommodating.
But he was focusing on playing against Italy, not the World Cup, saying "I'll do the best I can here and hopefully I'll be with the team there."