Jones will be a major loss for the Dragons

Doctors say the 29-year-old Kiwi's operation was a total success. He has been ordered to take a total rest and will be out for up to eight weeks.

In five weeks' time, doctors will assess his progress and will say when he might be able to play again.

On the plus side, team-mate Julien Rinaldi's leg injury is not serious.

Jones was the Dragons' most high profile summer signing and his loss will be keenly felt by the team.

"It's not an ideal situation but that's rugby league," said chief executive Grant Mayer.

"You can't base your game around one fella and it's best that it happens now rather than later in the season."