AS pre-season training begins, some of Spain's top clubs will be prepared to kick-off the new season without key players.

And they will undoubtedly point an accusing finger at the Olympics for their predicament.

In Sergio Batista's Argentina squad alone, there are no fewer than nine players based in Spain.

These include some marquee players, too.

Fernando Gago (Real Madrid), Sergio Aguero (Atletico Madrid) and Leo Messi (Barcelona) are the most notable inclusions, as Batista prepares to unleash hell on the 15 other nations vying for Olympic goal.

Having struck football gold four years ago in Athens, the Argentinians are heavily favoured to go all the way once again.

For both Madrid clubs and Barcelona, however, a shock early exit would do just fine.

Their respective stars will have missed the bulk of pre-season preparations.

An appearance in the final on 23 Aug would effectively rule them out for the first two weeks of the league season, at least.

Even though Gago, Aguero and Messi all play different roles for their clubs, they will be sorely missed.

Real Madrid defensive midfielder Gago is slowly but surely emulating Fernando Redondo, the player he grew up idolising.

He added much-needed stability in Real's midfield as they successfully defended their La Liga crown last season.

ABSENTEE

Aguero, meanwhile, was a major reason Atletico Madrid finished fourth in La Liga last season, despite the departure of star striker and club captain Fernando Torres to Liverpool.

He scored 19 league goals en route to the club's best finish in over 10 years and will be a key absentee as Atletico face Champions League qualifying matches in August.

Messi's absence from Barcelona will be the most significant, however, as new coach Pep Guardiola prepares for life after Ronaldinho.

The Brazilian superstar's move to AC Milan has left 21-year-old Messi as Barca's most important player, although many will contend that he has been for quite some time.

Real and Barca will also be monitoring world governing body Fifa's ruling on over-aged players very closely.

But whether or not Real's Robinho and Barca's Samuel Eto'o are released to play in Beijing, it looks increasingly unlikely that either player will still be at his respective club come August.

Eto'o has been linked with a move away from the Nou Camp since last season, while Chelsea have stepped up their interest in Brazilian forward Robinho.

Either way, Spain's biggest clubs will be missing their top players for quite some time.

REAL MADRID