Coyne, 32, had been unavailable for Glory until only earlier this month due to transfer regulations following his loan extension at Chinese club Liaoning Whowin, who he had originally joined in a bid to make the Socceroos 2010 World Cup squad.

But the Achilles injury, which Coyne sustained at Glory training, comes as a blow with the seven-time Socceroos defender finally available for Perth after receiving his International Transfer Certificate.

"I'm devastated to miss the final push," Coyne told au.fourfourtwo.com. "The boys have acquitted themselves well in the past three or four weeks and I wanted to come in and make a difference.

"I'm very disappointed and I feel like I've let down a few people in Perth. I wanted to come in and re-pay them, try get some wins and put in some dominant performances so we could finish on a high, if not get into the finals."

Coyne explained he had a pre-existing acute Achilles tendonitis injury, before a training ground accident last week inflamed the problem.

"I went for a challenge on Howard Fondyke - it was two days before a game - and I might have clattered him so I pulled out of it and invariably I've hurt myself. I locked my heel into the turf and over-stretched it," Coyne said.

"The last two weeks I knew it wasn't right. I haven't been able to train, I've been wrapped in cotton wool.

"I've gone to a specialist on Friday and he said to me afterwards 'I don't think you'll be playing the rest of the year because it looks quite bad in there compared to last time'. The scan has then revealed a two-centimetre tear."

Coyne added: "The manager (Ian Ferguson) has been very, very professional and very good with me.

"He said he wanted me back to play but obviously it's more important that I'm ready, fit and strong for next year, rather than trying to play some games this year and breaking down and maybe being out for six or seven months rather than missing five weeks."