With only two places in the round of 16 available, 2008 champions Gamba and 2009 winners Pohang are well aware of the importance of making a strong start in what is expected to be a tightly contested Group E which also contains 2008 runners-up Adelaide United and four-time defending Uzbekistan champions Bunyodkor.

Play-off winners and three-time Asian champions Pohang, who beat Thailand's Chonburi 2-0 last month to earn a place in the Group Stage, began the new K-League season on Saturday with a 1-0 defeat at home by Ulsan Hyundai Horang-i - who also kick-off their AFC Champions League campaign on Tuesday against China's Beijing Guoan.

With coach Hwang Sun-hong looking to add to the back-to-back Asian Club Championship titles he won as a player with Pohang in 1997 and 1998, the Steelers bolstered their squad in the closed season with the signings of Romania forward Ianis Zicu fromBulgaria's CSKA Sofia and Serbian defender Zoran Rendulic.

And Hwang will also look to Derek Asamoah to continue the form shown in his maiden K-League campaign last season after the Ghana international scored seven goals in 31 appearances before playing a central role in the play-off win over Chonburi.

With the J.League season not starting until March 10, questions remain how Gamba will react to the post Akira Nishino era after the 2008 AFC Champions League winning coach ended his 10 year association with the club at the end of last season.

Korea Republic midfielder Lee Keun-ho, who scored 15 goals in the J. League last season, also departed to join K-League side Ulsan in January, although Gamba signed Japan defender Yasuyuki Konno from FC Tokyo.

After Gamba conceded 51 goals in the J.League last season, AFC Asian Cup winner Konno, who was only one of two players to play every minute in Qatar at the start of last year, will be crucial to any plans new Brazilian coach Jose Carlos Serrao has of matching Nishino's success.

Gamba reached the AFC Champions League Round of 16 for a third consecutive season last year before suffering a dramatic last-gasp 1-0 defeat by cross-city rivals Cerezo Osaka before finishing inside the top three in the J. League for the seventh time in the last eight seasons - with their only exception in 2008.

Former Sao Paulo and Suwon Samsung Bluewings coach Serrao will be assisted by Wagner Lopes, with the former Japan international initially considered for the role, before being ruled out for not possessing a J.League club coaching license.

Australia's Adelaide, who beat Indonesia's Persipura Jayapura 3-0 in the play-offs last month, face a tough opener in Tashkent against Bunyodkor, who the Reds beat in the 2008 semifinals before losing 5-0 on aggregate to Gamba in the final.

After filling in at center-back against Persipura, Ukrainian Evgeniy Levchenko will not feature in the Group Stage after being left of the Reds' squad in favor of Uruguayan midfielder Francisco Usucar, although Adelaide have bolstered their defense after re-signing Iain Fyfe.

The arrival of former Sydney FC defender Fyfe, who notched up 140 A-League appearances before joining Korean side Busan I'Park at the start of last year, coincides with the departure of Milan Susak to Chinese Super League side Tianjin Teda.

Fellow A-League side Brisbane Roar, who won the A-League Grand Final earlier this year, begin their maiden AFC Champions League campaign at home to Japanese Emperor's Cup winners FC Tokyo in Group F, which also includes Beijing and Ulsan.

In the West, last year's semifinalists Al-Ittihad begin their pursuit of a third AFC Champions League crown in Group B against Uzbekistan's Pakhtakor, while Qatar's Al Arabi make the short trip to Abu Dhabi to face fellow debutants Baniyas.

Al Ittihad have bolstered their impressive squad, which includes the likes of Saudi Arabia goalkeeper Mabrouk Zaid, 2005 AFC Player of the Year Hamad Al Montashari and midfield duo Mohammed Noor and Saud Kariri as well as exiting striker Naif Hazizi, with Egyptian midfielder Hosny Abd Rabo.

Rabo joined Al Ittihad in February after being named Player of the Tournament as Egypt won the 2008 Africa Cup of Nations.

Spanish coach Raul Caneda is the latest to be handed the task of bringing success back to the 2004 and 2005 AFC Champions League winners after replacing Matjaz Kek, who only took over from Dimitri Davidovic in December before departing last month with Al Ittihad struggling for domestic form.

Elsewhere, Qatar's Al Rayyan take on play-off winners Esteghlal of Iran and AFC Cup winners Nasaf face UAE side Al Jazira in Group A.

Esteghlal disposed of fellow Iran Pro League side Zobahan and Saudi Arabia's Al-Ittifaq in the play-offs to earn a fourth successive appearance in the Group Stage, while Nasaf make their first AFC Champions League appearance after beating Kuwait Sports Club at the end of last year to complete an unbeaten AFC Cup campaign.