Perez was still receiving treatment on his hamstring on Sunday but Arnold felt with youngster Mustafa Amini, he had a good replacement.

“Right now it’s too early to tell,” Arnold said of Perez.

“What a luxury to have Musti. The kid came on and went about his business. Nothing phases him.”

The Mariners will regain right back Pedj Bojic for the decider as he returns from suspension after receiving two yellow cards in the second leg against Brisbane.

Striker Matt Simon, who played the last 20 minutes against Gold Coast, is likely to return to full training on Tuesday after his freak foot injury.

Meanwhile, Brisbane Roar youngster James Meyer is almost certain to miss the match with a foot tendon injury.

Meyer scored the equalizer in Roar's 3-3 draw with the Mariners earlier in the season but coach Ange Postecoglou doesn't think he'll be fit for Sunday.

"He tells me he's going to be all right but he's not," he said.