Mexico's 2009 Clausura Championship is just hours away, and the country's two most popular sides, Guadalajara and America, have spent big in the close season to avoid a repeat of last year's disappointments.

Yet even with strengthened squads, these Mexican powerhouses will have their work cut out to secure the title, with last year's Apertura champions Toluca having kept their impressive squad intact. Furthermore, the likes of Cruz Azul, UNAM Pumas, Pachuca and Morelia all have aspirations of their own, having gone varying amounts of time without a Primera Division title.  

Group 1: Tough to call
On paper at least, two clubs look capable of dominating this section: Santos Laguna, a semi-finalist last time out, and perennial candidates Pachuca. That said, the former have lost two of their best defenders in Fernando Ortiz and Edgar Castillo, while Los Tuzos will face the additional task of trying to balance their league and Copa Libertadores commitments.

This could provide an opening for Atlante, who surprised many by making the Apertura semis last year with a balanced side and no big-name stars. Also fancying their chances will be Monterrey, despite recently parting company with coach Ricardo La Volpe because of financial differences. Completing the group are two clubs with serious relegation concerns, Indios Juarez and Puebla, meaning the pair will be waging their own private battle against the drop every step of the way.

Group 2: Big names clash
As fate would have it, the country's four most popular sides - Guadalajara, America, Cruz Azul and Pumas - find themselves together in this section. Last time out, the latter two made the end-of-season play-offs, while Chivas and Las Águilas were left licking their wounds after coming up short.

Both those clubs are understandably determined to avoid a repeat of that in the 2009. America, who start their campaign under mounting pressure after their early exit from the Interliga, have re-signed Mexico international midfielder Pavel Pardo from Stuttgart and also have the likes of Fernando Ortiz, Edgar Castillo and Jean Beausejour in their impressive squad. Guadalajara, for their part, have brought centre-back Aaron Galindo back to his homeland after two seasons with Eintracht Frankfurt, and have two other big-name arrivals in Jared Borgetti and Carlos Ochoa.  

Pumas and Cruz Azul, meanwhile, will be aiming to build on the promise shown last season. The former have an unchanged squad, while the latter have left their nucleus intact and brought in three new faces. Then there are Morelia and Tecos UAG who, if their form in the recent Interliga is anything to go by, will not be happy to just make up the numbers.

Group 3: Defending champions and the rest
In contrast to the first two sections, Group 3 looks to have a clear favourite in Toluca. The 2008 Apertura champions have made minimal changes and look very capable of continuing last year's form. Things are more even among the remaining five sides, although Tigres could be the pick of the punch, having invested heavily in new players in a bid to capture their first league title since 1982. Another who will go into the campaign in upbeat mood are Atlas, their young side having narrowly missed out on a Copa Libertadores berth via the Interliga.

San Luis, who finished top of the overall standings in the last league championship, face a challenging start this year, having just lost coach Raul Arias and several key players. For their part, Necaxa take a renewed squad into the campaign, but it remains to be seen how quickly they can gel. Last but not least are Jaguares, who continue to mystify fans and observers alike. Can their talented squad finally realise its potential this season and make it out of their group to the play-offs?

Each club's aspirations aside, excitement is mounting ahead of what is sure to be another dramatic, emotion-filled season in Mexico. Kicking things off will be the Tecos-Indios clash, ahead of the weekend's headline game on Saturday between Cruz Azul and Chivas.

All you have to do now is sit back and enjoy the action, and let FIFA.com keep you up to date with developments every week.