Japan, whose coaching situation is in limbo with current incumbent Ivica Osim recovering from a stroke earlier this month, are favourites to reach the next stage as pool winners.

And with only two spots available in the fourth stage - another group phase consisting of two pools of five - Oman, Thailand and Bahrain are expected to battle for the final berth.

Thailand will be confident of overcoming Oman after recording a 2-0 victory in the group stage of July's AFC Asian Cup.

But Oman's Argentinian coach Calderon is confident his side will be challenging when the groups are decided in September next year after holding eventual champions Iraq and 2006 World Cup qualifiers Australia in July's AFC Asian Cup.

"Our group is very tough but the mission is not impossible because there are two tickets available from the group," he said.

"We can make it to the next round but we must put a lot of effort and prepare very well to do so."

Bahrain coach Macala, who guided Oman to their first AFC Asian Cup finals appearance in 2004, is backing his side to be in contention and build on their AFC Asian Cup group-stage victory over eventual semi-finalists South Korea.

"We have a tough task because Japan are the favourites in the group and the second place from the group is between Oman and Bahrain. However, we must play good football and we should never underestimate Thailand because they can cause troubles for all the other teams in the group," said Macala, who guided Kuwait to the Gulf Cup title in 1996 and AFC Asian Cup semi-finals in the same year.

"Our group is hard because we have Japan who are one of the top teams in Asia and there is also Oman, who I previously coached, while Thailand are one of the best developing teams in Asia recently."

Despite being overwhelming favourites to qualify from Group B, Japan - who have reached the finals of the last three World Cups and advanced to the second round in 2002 - are remaining cautious over their chances.

Japan Football Association president Saburo Kawabuchi said: "We've been drawn in a tough group. There are not any opponents we can beat easily.

"But we must get through this round and we are determined to advance to the final round of the qualifiers by any means."

JFA technical director Takeshi Ono added: "Since every team has got through tough matches, there'll be no easy games. We have to be aware that all the upcoming games will be close and we must be prepared for them."