DIEGO COSTA is the fighter who plans to KO his countrymen in Brazil.

FIGHT, FIGHT, FIGHT FOR THIS LOVE: Costa will fight to be a Spanish hero

Costa is seen as a traitor by many Brazilians for turning his back on the Samba stars to play for Spain.

But he doesn't care and will fight tooth and nail to make sure his adopted nation come out on top at the World Cup.

Brazil-born Costa, who is on the verge of a £32m move to Chelsea, said: "My game is to fight, to fight and to fight for every ball. That is my style.

"I am a calm player but I do not accept anyone showing me or my team-mates a lack of respect. Spain is the world champion and needs to defend this title. We will give everything to make it happen.

"I have confirmed that Spain is my country and the Spanish people are behind me. The criticism of my decision does not affect me.

"Brazil are serious contenders too but they are under a lot of pressure from their supporters. The people expect them to be in the final and that makes it tough for them."

Costa talks the talk but his fighting spirit has got him into trouble in the past.

He's been sent off for headbutting, and was once banned for punching an opponent and threatening a referee.

PAY THE COSTA BE THE BOSS: Diego Costa turned his back on Brazil to play for Spain

But Atletico boss Diego Simeone believes his fiery nature is the quality which could help Costa lead Spain back to glory after their 2010 triumph.

"Diego Costa is the type of player that any coach desires in their team," said the former Argentina star. "He is always fighting for the ball, with huge pride and constant effort.

"His choice to play for Spain was a personal one and we have to respect it. I am totally convinced he will have an excellent World Cup for the Spanish team.

"I don't think there will be any controversy with him in Brazil. He is a warrior who gives the maximum effort possible. Could he win the trophy with Spain? Yes, he could."

Costa has always been a fighter and spent his early years playing street football in the Brazilian city of Lagarto.

"I was used to seeing players elbowing each other in the face and thought it was the norm," he said. "On the pitch I fought with everyone. I had no respect for the opposition. I thought I had to kill them."

Costa claims he has cleaned up his act in recent years - but he still retains an edge that could make him hard to stop at the World Cup and in the Premier League next season.

A run-out against El Salvador last Saturday proved Costa is over the hamstring injury which caused him to limp out of the Champions League final defeat to Real Madrid.

He now hopes to make his competitive debut for Spain against Holland tomorrow.

Costa has actually played as many times for Brazil after appearing in two of their friendlies last year.

But his former coach at Valladolid, Jose Luis Mendilibar, believes Brazil made a huge mistake by ignoring the 25-year-old for so long.

He said: "I have worked with Diego and he is tremendously powerful. Brazil have missed out on a valuable player and Spain have picked up an important piece."

"People talk about his rebel character. But he is a disciplined player. I'd prefer a player like him in my squad any day."

So, it seems, would Brazil. Their loss could well be Spain's gain.