BY THE time the Olympics officially open on Friday night the football tournament will be comfortably underway.

The competition, for under-23 players with three overage players allowed, kicks off tomorrow.

Favourites Argentina take on Serbia and Montenegro in Group C and hosts Greece, hoping for a dream double following the Euro 2004 success of their senior team, play South Korea in Group A.

Tomorrow?s other games see Mali play Mexico (Group A) and Tunisia take on Australia, captained by Rangers? Craig Moore, in Group C.

The other eight teams - Paraguay, Japan, Ghana, Italy (Group B); Costa Rica, Morocco, Iraq and Portugal (Group D) - are all in action on Thursday.

Though the Olympic tournament lacks the glamour of the World Cup and other major championships, it has been growing in popularity and importance in recent years, partly due to the fresh look of its line-up.

Notable absentees this year are Brazil, Germany, Spain and holders Cameroon while the likes of Mali, Iraq, Paraguay and Serbia and Montenegro can enjoy a rare chance to show what they can do on a global stage.

Similarly, followers of Greece and Portugal, who met in the final of Euro 2004 a month ago, will be eager to keep up the momentum set by their senior sides.

Portugal have called up Cristiano Ronaldo, the 19- year-old Manchester United winger who was so impressive in their run to the Euro final, while striker Dimitris Papadopoulos is the only Greek player to appear in both competitions.

Argentina, losing finalists in 1996, have used the three over-age players rule to the full, bringing in the experience of Barcelona striker Javier Saviola and 31-year-old Valencia defender Roberto Ayala.

There is a strong African presence as the continent seeks its third successive Olympic title, following the gold medals for Cameroon in Sydney and Nigeria in Atlanta. Tunisia and Ghana look the strongest though Mali and Morocco are also dangerous.

Europe?s challenge will be spearheaded by a classy- looking Italian team, which includes midfielder Andrea Pirlo and striker Alberto Gilardino. They start against Ghana on Thursday with Paraguay taking on Japan in the other Group B game.

In the women?s event, in the absence of 2000 winners Norway, world champions Germany and the United States are likely to lead the challenge for the gold medals.