Adelaide play semi-pro outfit Waitakere of New Zealand in the play-in qualifier in Tokyo on December 11. The winner - expected to be the A-League franchise – meets Gamba Osaka in the quarter final.

Costanzo, 32, says the emergence of the former Cruzeiro player has given the Reds hope that a potentially fatigued Gamba may succumb to the revenge-seeking Reds.

Alemao, who turns 26 on Saturday, has been a revelation in recent weeks in a freer role behind the strike line. He looms as the man who could make the difference against the classy J-League power - who haven't seen him play in the ACL.

"When he arrived he was probably played out of position as a full back," Costanzo tells au.fourfourtwo.com.

"He can be a bit more adventurous now in midfield. It does open up the options. And he frees up Jonas [Salley] and Travis [Dodd]."

Alemao had been the slowest of the Reds' Brazilian signings to warm to the A-League. But with a marriage this week (to Fernunda de Sosa Oriani in Adelaide) and promising form on the domestic front, he's looming as a real threat should Osaka meet the Reds once again.

"He's done really well. He's made a difference to us and we can use that in Japan," adds Costanzo.

The former Marconi defender, capped six times for the Socceroos, says the key to stopping Gamba is to shackle their mobile midfield. And the Reds have the right sort of players to do that.

"We had a few players out," he says of the ACL final. "And they had some quality midfielders who we'll need to shutdown.

"If we can do that and the fact that we've got so many players coming back...we were down to bare numbers for the final."

That included Costanzo who picked up a needless yellow in Osaka ruling him out of the return leg.

"Maybe they would have started their holidays already, let's hope so," he joked.

"When we played them they were well into their season. It could be a good time to get them."

With just two matches left in the J-League, Gamba are out of the running to win the title with Kashima Antlers now firm favourites. Akira Nishino's Gamba was beaten 4-0 at home on the weekend against Frontale.

Alemao was left out of the Reds' ACL campaign with Aurelio Vidmar having to choose three out of his four visa players.

That rule also kept Jonas Salley out of United's run through Asia. And the Ivory Coast-born midfield screener is the ideal man to shut down Gamba's flowing midfield.

"Jonas was probably a player we missed [in the ACL]. And even Fabian Barbiero didn't play the first leg against Gamba," added Costanzo.

"Daniel Mullen is another player who can come in and of course we should have Paul Agostino available for selection. So they all help.

"It'll be a different Adelaide United. You won't see the same result. We do owe them one."