LA PLATA, Argentina, June 7 (Reuters) - Substitute Lionel Messi scored his 38th goal for Argentina as they breezed past Slovenia 2-0 in their final World Cup warmup on Saturday.
Messi, his country's second highest scorer after Gabriel Batistuta, had not found the net in an international since a 5-2 qualifying win over Paraguay in Asuncion in September.
Argentina's captain began the match on the bench along with other key players like Sergio Aguero and Angel Di Maria, with coach Alejandro Sabella fearful of his squad being caught up in the spate of injuries affecting other World Cup finalists.
Sabella used the friendly at the Estadio Unico to test an alternative tactical plan with three at the back and five across the middle before changing things in the second half.
Winger Ricky Alvarez opened the scoring in the 12th minute with a low left-foot shot from the edge of the box but two minutes later midfielder Lucas Biglia came off after receiving a knock and was replaced by Hugo Campagnaro.
In the 76th minute Di Maria lobbed the ball from the edge of the box to the left where Aguero headed it down to Messi, who had come on for Alvarez in the 57th, and he dinked it between two defenders and the goalkeeper.
"Now the hour of truth has come, the friendlies are over and we're going to Brazil full of desire," Messi told reporters after winning his 86th cap.
"We've managed to be a united and very strong squad and we did that as Alejandro wanted. We're more together than ever because of the dream we all have."
Biglia joined Rodrigo Palacio, who twisted his ankle in the 3-0 win over Trinidad & Tobago on Wednesday, and Martin Demichelis in nursing minor injuries as the squad headed for their tournament base in Belo Horizonte.
Argentina open their Group F programme against Bosnia at the Maracana in Rio de Janeiro on June 15 before meeting Iran in Belo Horizonte on June 21 and Nigeria in Porto Alegre four days later. (Reporting by Luis Ampuero, writing by Rex Gowar, editing by Tony Jimenez)