24 teams from 13 nations participated in the CONCACAF Champions League 2008–09 from the North American, Central American, and Caribbean zones. Below is the qualification scheme for the 2008-09 competition:[2]
* - New England was both the 2007 U.S. Open Cup winner and the MLS Cup 2007 runner-up, so Chivas USA has claimed USA4 as the 2007 MLS Supporters' Shield runner-up.
** - Saprissa were both the Invierno 2007 and Verano 2008 winner, so Alajuelense has claimed CRC2 as the Verano 2008 runner-up.
*** - Luis Angel Firpo were both the Apertura 2007 and Clausura 2008 winner, so Isidro Metapán has claimed SLV2 as the Clausura 2008 runner-up.
**** - San Francisco was both the Clausura 2007 and Apertura 2008 winner, so Tauro has claimed PAN2 as the Apertura 2008 runner-up.
Format
There was a two-legged Preliminary Round for 16 clubs, with the 8 winners advancing to the Group Stage. They were joined by the other 8 teams who were seeded directly into the Group Stage. The clubs involved in the Group Stage were placed into four groups of four with each team playing the others in its group in both home and away matches. The top two teams from each group will advance to the Knockout Rounds, which will consist of two-legged ties. The Final Round, to be held in late April 2009, will also be two-legged. Also, unlike the previously contested CONCACAF Champions' Cup, the away goals rule will be used in the CONCACAF Champions League.[3]
The draw for the Preliminary Round was held on 11 June 2008 in New York City. The first legs of the Preliminary Round were played from 26 August 2008 to 28 August 2008, while the second legs were played from 2 September 2008 to 4 September 2008.[4]
The draw for the Championship Round was held on 10 December 2008. In each round, teams will play their opponent once at home and once away. The four group winners from the Group Stage will play the second leg at home in the Quarterfinals. The order of the home and away matches for the Semifinals and Finals were determined at the draw.
In all rounds, if two teams are tied after both legs the team with the most away goals is the winner. If the two teams are also tied in away goals then two fifteen minute halves of extra time are played. If the two teams are still tied on total goals after extra time a penalty shootout determines the winner.
The first legs of the Quarterfinals will be played from 24 February 2009 to 26 February 2009, while the second legs will be played from 3 March 2009 to 5 March 2009.
The first legs of the Semifinals will be played from 17 March 2009 to 19 March 2009, while the second legs will be played from 7 April 2009 to 9 April 2009.
The first leg of the Finals will be played from 21 April 2009 to 23 April 2009, while the second leg will be played from 28 April 2009 to 30 April 2009.