Lawrence Thomas receives a boot to the face. Credit:AAP

Roy O'Donovan must wait to learn his fate but faces a "potentially lengthy" ban for his ugly A-League grand-final challenge on Lawrence Thomas.

Football Federation Australia's independent disciplinary and ethics committee deliberated after a three-hour hearing in Sydney on Tuesday evening before opting to defer its decision on what punishment the Newcastle striker should serve.

But it's not looking good for O'Donovan, who could spend a small chunk of next season on the sidelines after his studs caught Melbourne Victory's goalkeeper flush in the jaw in the 93rd minute of this month's 1-0 decider.

"This is a potentially lengthy sentence and we just need to be clear on our reasoning," committee chairman John Marshall SC said.