Perth Glory goalkeeper Brad Jones is expected to miss a significant chunk of the A-League Men's season due to a lingering knee injury.

The former Socceroos and Liverpool gloveman managed just five appearances last season mostly due to a serious calf injury and he is still sidelined by the knee injury he suffered late in the campaign.

No time frame has been set for the 40-year-old's return, but Glory announced on Wednesday they had signed 24-year-old goalkeeper Pierce Clark as an injury replacement.

Luckily for Glory, veteran Liam Reddy is fit and on track to feature in the club's season opener against Western Sydney at CommBank Stadium on Sunday.

Clark spent stints with Victorian NPL clubs Dandenong Thunder, South Melbourne and Bentleigh Greens, and he was also formerly a part of the youth set-up at the Newcastle Jets.

"Pierce has come in and trained the house down," Glory head coach Ruben Zadkovich said.

"He has a real appetite to work hard and is striving constantly for improvement in his game.

"He is battle-hardened by a long string of games in the Victorian NPL and that resolve will make him an important part of our squad."

Glory collected the wooden spoon last season and are being widely tipped to struggle again.