Kennedy picked up the injury on Wednesday and there are fears he could be ruled out for the entire A-League season.

The Jets stopper was in competition with new signing Jack Duncan for the starting number one jersey following the departure of Mark Birighitti overseas.

The 29-year old will see a surgeon next week in Sydney once the swelling subsides.

The Jets said in a statement: "Newcastle Jets regret to advise its Members, supporters and media that experienced custodian Ben Kennedy sustained an injury to his Achilles tendon at training on Wednesday.

"The shot-stopper saw a specialist and had scans late this afternoon. The Club will provide further information regarding the extent of the injury when it is known."

Duncan will start in goals for the Jets in the season-opener against Adelaide United on Sunday. Young keeper Pierce Clark will take the reserve goalkeeper's spot on the bench.