Mansour Ebrahimzadeh's side was the surprise of the 2010 edition of the competition as the club from Ishfahan saw off illustrious names such as Al Ittihad, Al Hilal, Bunyodkor and Pohang Steelers to progress to the final in Tokyo.

Zobahan finally met their match against Seongnam Ilhwa in the Japanese capital but, after finishing second in the Iran Pro League to qualify once again, the Iranians will be hoping to improve on last year's performance and become the first club from their country to win the AFC Champions League since it was created in 2002.

They will certainly be favorites to emerge from their opening game with all three points against an Emirates side that is currently playing in the second division of the league in the United Arab Emirates.

Emirates qualified for the competition by winning the President's Cup but their joy was short-lived at home as they were also relegated from the top flight, but if there is one club in Asia that should know not to underestimate others it will be Zobahan.

Qatar's Al Rayyan and Al Shabab of Saudi Arabia will also meet in Group D as teams from the west of the continent attempt to win the title for the first time since the second of Al Ittihad's back-to-back triumphs in 2005.

The Saudi side also begin their campaign on Wednesday when they host Tehran giants Pirouzi in Jeddah with both sides keen to pick up three points in what is sure to be a keenly contested Group C.

Al Wahda of the United Arab Emirates and Bunyodkor complete the group and face off on Wednesday, just days after the Uzbek side completed the signing of 11 new players to bolster their pursuit of a first-ever continental title.

"A group of players left the team last season, but their places have been taken by worthy replacements," said coach Mirdjalal Kasimov. "I believe the team will now make every effort to achieve higher goals this season."  Among the new faces are Serbian trio Milo Trifunovic, Slavoljub Djordjevic and Sasa Dordevic as Bunyodkor aim to overcome the loss of key players such as former AFC Player of the Year Server Djeparov.

In the east of the continent, Suwon Bluewings have also been busy rebuilding their squad and the Korean FA Cup winners will begin their quest for a third Asian title in Australia when they take on Sydney FC.

Suwon, winners of the last two editions of the Asian Club Championship in 2001 and 2002, have embarked on a significant spending spree with the Samsung-backed club bringing in Korean internationals Jung Sung-ryung, Choi Sung-guk and Lee Yong-rae as well as Uzbek striker Alexander Geynrikh.

"About 60 percent players in our regular starting line-up are new," said coach Yoon Sung-hyo, who will be starting his first full season as head coach after taking over from Cha Bum-kun midway through last year.

"Striker Choi Sung-guk and national team goalkeeper Jung Sung-ryong have played for Seongnam. Jung has experience of winning the ACL last year and I hope this will also help us.

"It's true that away matches in ACL are not easy in terms of stamina and team condition but we have to overcome this problem if we want to be No. 1 in Asia."  Japan's Emperor's Cup winners Kashima Antlers have also been drawn in Group H and will be hoping to deny Suwon the honor of being crowned Asian champions. Oswaldo Oliveira's side start their campaign in China when they take on Shanghai Shenhua.

Chinese Super League champions Shandong Luneng, meanwhile, travel to Korea Republic to meet former champions Jeonbuk Motors in Group G as Choi Kang-hee's side look for a repeat of their 2006 triumph.

The pair are joined in Group G by debutants Cerezo Osaka, who were surprise third-place finishers in last year's J.League standings. Levir Culpi's side entertain Indonesian champions Arema Indonesia.