Eduardo da Silva will sing both the Brazilian and Croatian national anthems at the opening game of the 2014 World Cup.
The former Arsenal striker is a Brazilian by birth but has played for Croatia through nationalisation after signing for Dinamo Zagreb in 1999 and staying until 2007.
Eduardo has played 63 times for Croatia, scoring 29 goals and is part of Niko Kovac's squad that will face Brazil next Thursday.
His mother is quoted by news agency SNTV as saying: "I'm rooting for Eduardo da Silva.
"I understand that it is very important for him but I'm also rooting for Brazil. Eduardo vs. Brazil.
"He has said he will sing two anthems. He is Croatian for work, in his heart he is Brazilian."