Ronaldinho, rumored to be leaving Barca, has not played for Brazil's senior national team in recent matches, but he publicly lobbied for a spot in Brazil's Olympic roster as one of its overage players.
Also in the Brazil squad are forwards Robinho (Real Madrid), Alexandre Pato (AC Milan) and Jo (recently signed by Manchester City) and playmaker Diego (Werder Bremen).
Argentina's squad includes Messi and fellow 2006 World Cup team veterans Juan Roman Riquelme, Nicolas Burdisso, Javier Mascherano and Oscar Ustari.
While U.S. Olympic men's coach Peter Nowak is still not ready to announce his 18-player roster (with three possible overage players) for the Olympics that begin next month in China, several other teams have named their teams.
Italian-American Giuseppe Rossi is in Italy's team.
New Zealand's squad features former MLS stars Ryan Nelsen, now with England's Blackburn Rovers, and Simon Elliott, and a pair of current U.S. collegians, Michael Boxall (UC Santa Barbara) and Craig Henderson (Dartmouth University). Steven Old played at St. John's.
Senior national team veteran Yasuhito Endo heads Japan's Olympic team, which is Group B along with the USA, Nigeria and the Netherlands.
Nigeria's three overage players will be full internationals Osaze Odemwingie, Vincent Enyeama and Ikechukwu Uche. Its pre-Olympics tour of the United States was canceled, however.
Goalkeepers: Oscar Ustari (Getafe/SPA), Sergio Romero (AZ/NED)
Defenders: Pablo Zabaleta (Espanyol/SPA), Luciano Monzon (Boca Juniors), Ezequiel Garay (Real Madrid/SPA), Nicolas Burdisso (Inter Milan/ITA), Federico Fazio (Sevilla/SPA), Lautaro Acosta (Sevilla/SPA).
Midfielders: Fernando Gago (Real Madrid/SPA), Juan Roman Riquelme (Boca Juniors), Ever Banega (Valencia/SPA), Javier Mascherano (Liverpool/ENG), Jose Sosa (Bayern Munich/GER)
Forwards: Diego Buonanotte (River Plate), Sergio Aguero (Atletico Madrid/SPA), Lionel Messi (Barcelona/SPA), Ezequiel Lavezzi (Napoli/ITA), Angel Di Maria (Benfica/POR).
Mark Bridge (Sydney FC), Billy Celeski (Melbourne Victory), Adam Federici (Reading/ENG), Neil Kilkenny (Leeds United/ENG), Adrian Leijer (Fulham FC/ENG), Trent McClenahan (Hereford United/ENG), Mark Milligan (uncontracted), Stuart Musialik (Sydney FC), Nikita Rukavytsya (Perth Glory), Kristian Sarkies (Adelaide United), Matthew Spiranovic (FC Nuremberg/GER), Nikolai Topor-Stanley (Perth Glory), James Troisi (uncontracted), Tando Velaphi (Perth Glory), Ruben Zadkovich (Derby County/ENG), David Carney (Sheffield United/ENG), Jade North (Newcastle Jets), Archie Thompson (Melbourne Victory).
BELGIUM (short list of 38 players):
Goalkeepers: Logan Bailly (Racing Genk), Yves De Winter (Westerlo), Yves Ma-Kalambay (Hibernian/SCO), Simon Mignolet (Saint-Trond), Glenn Verbauwhede (Courtrai).
Defenders: Laurent Ciman (Club Brugge), Wouter Corstjens (Westerlo), Sepp De Roover (Groningen/NED), Reginal Goreux (Standard Liege), Vincent Kompany (Hamburg/GER), Massimo Moia (La Gantoise), Landry Mulemo (Standard Liege), Sébastien Pocognoli (AZ/NED), Jason Vandelannoite (Bursaspor/TUR), Anthony Van Loo (Roulers), Thomas Vermaelen (Ajax/NED), Jan Vertonghen (Ajax/NED)
Midfielders: Alessandro Cordaro (Mons), Marouane Fellaini (Standard Liege), Faris Haroun (Racing Genk), Maarten Martens (AZ/NED), Vadis Odjidja Ofoe (Hamburg/GER), Killian Overmeire (Lokeren), Gaby Mudingayi (Lazio/ITA), Jeroen Simaeys (Club Brugge), Anthony Vanden Borre (Genoa/ITA), Axel Witsel (Standard Liege)
Forwards: Moussa Dembélé (AZ/NED), Tom De Mul (Sevilla/SPA), Stijn De Smet (Club Brugge), Tom De Sutter (Club Brugge), Roland Lamah (Anderlecht), Jonathan Legear (Anderlecht), Kevin Mirallas (Lille/FRA), Mbo Mpenza (Larissa/GRE), Giuseppe Rossini (Mechelen), Bjorn Vleminckx (Mechelen) et Jeanvion Yulu-Matondo (Roda JC/NED).
Goalkeepers: Diego (Almeria), Renan (Internacional)
Defenders: Marcelo (Real Madrid), Ilsinho (Shakhtor Donetsk), Rafinha (Schalke 04), Thiago Silva (Fluminense), Alex Silva (Sao Paulo), Breno (Bayern Munich).
Midfielders: Lucas (Liverpool), Anderson (Manchester United), Hernanes (Sao Paulo), Ronaldinho (Barcelona), Diego (Werder Bremen), Thiago Neves (Fluminense)
Forwards: Robinho (Real Madrid), Alexandre Pato (AC Milan), Rafael Sobis (Real Betis), Jo (Manchester City).
ITALY (short list of 22 players):
Ignazio Abate (AC Milan), Robert Acquafresca (Cagliari), Salvatore Bocchetti (Genoa), Antonio Cadreva (Udinese), Luca Cigarini (Parma), Andrea Coda (Udinese), Andrea Consigli (Atalanta), Domenico Criscito (Genoa), Paolo De Ceglie (Juventus), Lorenzo De Silvestri (Lazio), Daniele Dessena (Parma), Sebastian Giovinco (Juventus), Claudio Marchisio (Juventus), Riccardo Montolivo (Fiorentina), Marco Motta (Udinese), Antonio Nocerino (Palermo), Andrea Ranocchia (Arezzo), Tommaso Rocchi (Lazio), Giuseppe Rossi (Villarreal), Andrea Russotto (Treviso), Salvatore Sirigiu (Citta di Castello), Emiliano Viviano (Brescia).
JAPAN (short list of 20 players):
Goalkeepers: Kaito Yamamoto (Shimizu S-Pulse), Shusaku Nishikawa (Oita Trinita).
Defenders: Hiroki Mizumoto (Kyoto Sanga), Hajime Hosogai (Shimizu S-Pulse), Naoaki Aoyama (Shimizu S-Pulse), Masato Morishige (Oita Trinita), Michihiro Yasuda (Gamba Osaka), Atsuto Uchida (Kashima Antlers), Maya Yoshida (Nagoya Grampus)
Midfielders: Yasuhito Endo (Gamba Osaka), Takuya Honda (Shimizu S-Pulse). Hiroyuki Taniguchi (Kawasaki Frontale), Yohei Kajiyama (FC Tokyo), Keisuke Honda (VVV/NED), Tsukasa Umesaki (Urawa Red Diamonds).
Forwards: Yohei Toyoda (Montedio Yamagata), Tadanari Lee (Kashiwa Reysol), Shinji Okazaki (Shimizu S-Pulse), Shinzo Koroki (Kashima Antlers), Takayuki Morimoto (Catania/ITA).
Goalkeepers: Liam Little (Otago United), Jacob Spoonley (Miramar Rangers).
Defenders: Michael Boxall (UC Santa Barbara), Ian Hogg (Hawke's Bay United), Sam Jenkins (Hawke's Bay United), Ryan Nelsen (Blackburn Rovers), Steven Old (Macarthur Rams), Jack Pelter (Unattached), Aaron Scott (Waikato FC), Cole Tinkler (Team Wellington).
Midfielders: Jeremy Brockie (Hawke's Bay United) Simon Elliott (Unattached), Craig Henderson (Dartmouth University), Cole Peverley (Hawke's Bay United), Shaun van Rooyen (Waikato FC).
Forwards: Daniel Ellensohn (Team Wellington) Chris Killen (Celtic), Sam Messam (Hawke's Bay United).