Hwangbo's charges lead the way in Group F after posting two wins and a draw and unbeaten FC Seoul know another three points at Seoul World Cup Stadium would secure passage to the knockout stage should Al Ain fail to beat China's Hangzhou Greentown in the UAE.

But while FC Seoul have made a strong start to their continental campaign, which included a 1-1 draw in Japan two weeks ago, the defending champions have made a stuttering start to the domestic season after managing just one win in six games.

"In the away game against Nagoya, FC Seoul did not perform as well as expected as the game finished 1-1. But in the upcoming match with Nagoya on Tuesday, we want to win to improve our position in the group," said Hwang, who will have to watch from the stands after being handed a one-match suspension.

"I would like to apologize for the slow start in K-League, however, we are getting better and better slowly with every game. The reason for FC Seoul having a slow start is because the rest of the teams are focusing on the league and sharpen their knife toward our team as we were the defending champions." With last 16 aspirations of their own, J.League champions Nagoya will look to continue their Group F revival after demolishing former champions Al Ain of the UAE 4-0 last week to claim a first win of the campaign despite their enforced break from domestic action following last month's devastating earthquake and tsunami.

Nagoya sit level on points with Hangzhou Greentown, three points adrift of FC Seoul, with Al Ain rooted to the foot of the table with just one point and in desperate need of a win over the Chinese Super League side to keep their qualification hopes alive.

Hangzhou have enjoyed a perfect start to the new domestic season with a 100% record after three games, although Al Ain are boosted by the fact a Chinese side has never claimed a point from an AFC Champions League game in the Middle-East.

Elsewhere, pole position in Group H is on the line at the National Stadium in Tokyo as Kashima Antlers welcome Suwon Samsung Bluewings to their temporary home.

After the Kashima Soccer Stadium was damaged during last month's earthquake, Oswaldo Oliveira's side will play their three remaining AFC Champions League fixtures in the Japanese capital after picking up five points from three games on the road following a reshuffle of the Group H fixtures.

And with Suwon amassing a virtually identical record at the halfway stage, which included a 1-1 draw in Korea two weeks ago, a victory for either side would create a welcome cushion with just two games remaining.

With Suwon and Kashima leading the way with a three-point advantage, winless duo Shanghai Shenhua and Sydney FC are both in urgent need of a first win of the group stage at Hongkou Stadium.

Sydney, who must play their final three games away from home, are boosted by the return of captain Terry McFlynn and influential playmaker Nicky Carle, who both missed last week's 3-0 home defeat by Kashima.

Meanwhile in the West, Iran's Zobahan will look to secure a place in the last 16 to continue their pursuit of the AFC Champions League title which eluded them last year when the 2010 beaten finalists entertain Qatar's Al Rayyan.

After beating the Emir's Cup winners 3-1 in Doha two weeks ago, Zobahan will be confident of claiming a third win in four games in Group D which would be enough to secure qualification for the knockout stage as long as Al Shabab beat Emirates of the UAE.

Ghasem Hadadifar scored in the win over Al Rayyan but the midfielder will miss the return fixture due to suspension, while winless Al Rayyan will look to post a first win of the campaign without striker Itamar after the Brazilian was sent-off against Zobahan although Daniel Goma and midfielder Hamid Ismaeil are both available after serving bans.

Al Shabab beat Emirates 4-1 in Riyadh at the start of April, but will be without the services of suspended defender Mesaed Al Henzi.

While Al Rayyan are struggling in Group D, compatriots Al Sadd will secure passage to the last 16 from Group B with victory over Al Nassr in Saudi Arabia if struggling Pakhtakor fail to beat Esteghlal.

Al Sadd's Algerian defender Nadir Belhadj is suspended after being sent off in the 1-0 win over Al Nassr, while midfielder Wesam Rizik is also ruled out after picking up two yellow cards.

Al Nassr, who are three points adrift of Al Sadd after suffering their first defeat of the campaign two weeks ago, will also be forced to reshuffle their side with defenders Mohammed Eid and Ahmed Dokhi suspended, although defender Omar Howsawi and midfielder Ahmad Abbas are available to return.

After suffering a second defeat of the competition two weeks ago in Iran, winless Uzbek side Pakhtakor are in desperate need of victory against Esteghlal, who are level on points with Al Nassr.

Defender Komoliddin Tadjiev is available for Pakhtakor after missing the 4-2 defeat in Iran although striker Temurkhuja Abdukholiqov is suspended, while Esteghlal are boosted by the return of defender Hanif Omran Zadeh.