A dramatic 4-3 triumph in Melbourne on April 9 helped Gamba open up a three-point lead over Thailand's Chonburi FC and Nishino is eager for a repeat against the A-League side at Expo '70 Memorial Stadium on Wednesday in order to inch closer to a last-eight spot.

"I want to secure qualification over the next two matches against Melbourne and at Chonburi," he said.

"Otherwise, we could let Melbourne back into the race."

However, Nishino faces a selection headache with the possibility of his top two goalkeepers being sidelined for the encounter and could be forced to throw youngster Atsushi Kimura into the fray against Ernie Merrick's men.

First choice Yosuke Fujigaya is definitely out after dislocating his shoulder in the first half of the goalless draw with Kashima, while replacement Naoki Matsuyo is also struggling with a shoulder injury sustained in a collision with an Antlers player during the same game.

However, Nishino is still holding out hope the 34-year-old will be able to face Melbourne

"If he can manage to play, then I will play him," he said.

Melbourne's initial foray into continental competition has seen an opening victory over Chunnam Dragons offset by subsequent defeats to Chonburi and their Japanese opponents.

And Merrick admitted even if Victory do triumph on Wednesday, it will still be tough for them to top the group.

"If we beat them, they still have to lose points to another team and I'm not so confident about that to be honest," he said.

"But that won't stop us from giving it our best shot. The lads have been buoyed by all their performances, they've just been disappointed with the results. They are pretty keen to go again in Japan. They really want another go at Osaka."

In the group's other game, Chonburi host Chunnam still harbouring hopes of landing an unlikely last eight berth.

Defender Natthapong Samana and midfielder Chonlatit Jantakam are suspended for the crucial encounter but defenders Phaisan Pona and Surat Sukha are set to return after recovering from injury.

And boss Jadet Meelarp is under no illusions about the importance of the clash, particularly after the 1-0 defeat in Korea two weeks ago.

"These next two games are very important for our team and we hope that we can create a big shock for Thai football," he said.

"We need three points as we want to qualify for the next stage and if we beat Chunnam then we can turn our attention to our next home match against Gamba Osaka."

Chunnam coach Park Hang-seo admitted Wednesday's match represented the last chance saloon for his side.

"Right now we have only three points and our chances of qualifying for the quarter-finals are very slim," he said.

"We have to win all our remaining matches but we will try our best and if we beat Chonburi, then we will still have a chance."