Greco capped 4 times for the Italy U15 team in June 2003. He also capped 4 times for the same U17 feeder team in the whole 2003–04 season. He played 7 friendlies for Italy national under-17 football team and played all 4 matches in 2005 UEFA European Under-17 Football Championship. The team finished as the third.http://en.archive.uefa.com/competitions/under17/history/season=2005/round=1920/group=2493.htmlhttp://en.archive.uefa.com/competitions/under17/history/season=2005/round=1921/match=80817/index.htmlhttp://en.archive.uefa.com/competitions/under17/history/season=2005/round=1922/match=80822/report=lu.html The team also went to 2005 FIFA U-17 World Championship. The club finished as the third of Group C and failed to quality to quarter-finals.
