Lucas Barrios says he has not betrayed Argentina despite opting to represent Paraguay at the World Cup finals in South Africa.
The striker was recently called into the Paraguayan ranks after receiving citizenship a matters of weeks ago.
Barrios was born in Argentina but has a Paraguayan mother and he could have played for Diego Maradona's team had he received a call-up.
No such call was made, and the 25-year-old chose to link up with the Group F hopefuls instead, who take on Italy, New Zealand and Slovakia this summer.
He insists the decision was not made out of spite, though, telling Germany's Bild am Sonntag newspaper: "I am not angry with Maradona for not giving me a chance. Anyway, I took the first steps towards being able to play for Paraguay in October 2009.
"I am proud to be Paraguayan, thanks to my mother who was born in Asuncion. But I also have an Argentinian passport.
"It was not a tough choice at all - it is a pleasure! I am very happy to be in the squad and there is nothing more beautiful than that, and I am thankful to everybody who has supported me."
Barrios has scored three goals in his first three appearances for his chosen country and will be looking to continue his impressive form on a club level.
The striker arrived in the Bundesliga backed by the recommendation of 49 goals in 53 games for Chilean side Colo Colo and he netted 19 times in his first season in Germany with Dortmund.
That has already attracted the interest of several top European sides and the front man could be in the shop window as he looks to help his new nation become an unexpected challenger in the tournament.
He added: "We could be the surprise of the World Cup. We have a good team, above all in the attack."
Barrios and his team will face a tough ask to make progress, with current holders Italy their first opponents on 14 June.
The front man refused to fear the Azzurri and said he would be looking to secure three early points.
He said: "Italy are the world champions and have a good team - they are a team who always do well in tournaments and I respect them, but that respect disappears when you are on the field."