The 36-year-old suffered the injury after taking a goalkick just seven minutes into the Mariners' 4-1 win against Perth Glory.

The injury has thrown Bosnich's immediate playing future into doubt with his seven-week contract with the Gosford-based A-League club due to expire next weekend.

Bosnich had impressed in his first three games back, but the former Manchester United and Chelsea shot-stopper's return looks to be over, in the short-term at least, with Mariners manager Lawrie McKinna revealing he is yet to talk to the player about the possibility of extending his deal.

"We had not spoken about his future, Mark was just keen to get through the seven weeks," McKinna said.

"It took his body a while to get used to the level of training, and he does train hard.

"On Monday, when we know the extent of the injury, it could be a couple of weeks or it could be longer term.

"We will sit down with Mark but it looks highly likely he will miss next week."

Bosnich himself is hopeful the injury will not be too serious.

"I will have a scan on Monday. Everything has gone well while I have been here, so when something goes bad I will have to take it like a man," said Bosnich.

"I do not think it is that serious. My body has not done this level of serious training for a while so maybe that had something to do with it.

"But we will not know until Monday, but I will be playing again this season, hopefully this spell. I have had a great run while I have been here and I have to take the good hits with the bad."

The Mariners decided to take a punt on Bosnich after their first-choice goalkeeper, Danny Vukovic, was handed a five-game ban for striking a referee in last season's A-League grand final.

Bosnich had not played professionally since leaving English Premier League side Chelsea amid allegations of drug use in 2002.