The 31-year-old hopes he is able to turn out for the last two games of the Clausura championship with Independiente against relegation-threatened San Lorenzo and title-chasing Tigre.
"I don't feel physically or mentally as well as I'd like. I feel like I have to force myself for the day-to-day [activities] and came to the conclusion I would put a full stop to my sports career," he said after Tuesday's practice with the club from the suburb of Avellaneda.
The younger brother of Inter Milan striker Diego Milito, he made his first division debut with Independiente in December 1997.
He helped them win the Apertura league title in 2002 before moving to Spain the following year expecting to join Real Madrid but failed the medical because of a knee problem.
He signed for Real Zaragoza instead and spent four seasons with them including victory in the King's Cup in the 2004 final against Real Madrid.
Milito moved to Barcelona in 2007 and was part of the squad who won the Champions League in 2009 and 2011 and three successive Liga titles but saw limited action through injuries including missing the whole of the 2008/09 season. He returned to Independiente last August.
He won last of his 42 Argentina caps in the 2011 Copa America quarter-final defeat by Uruguay. He also played at the 2006 World Cup in Germany and the 2007 Copa America in Venezuela.
