Utility-player Danny Addy - who can operate at centre, half-back, hooker or in the back-row - suffered a “complex” knee injury in last Sunday’s pre-season game against Hull.
Rovers begin their Betfred Super League campaign at home to Wakefield Trinity on Friday, February 2 and face champions Leeds Rhinos at Elland Road six days later.
A club spokesman said: “Hull Kingston Rovers can unfortunately confirm that Scotland international Danny Addy has been ruled out long-term with a complex knee injury.
“He suffered the injury in the first half of Sunday’s pre-season friendly against Hull FC, with scans (on Monday) revealing the full extent of the damage he has suffered.
“Danny will now see a specialist this week to discuss the best options for his surgery and recovery, with it thought at this stage that the versatile forward is likely to miss the full 2018 season.
“Danny will still remain fully involved at the club whilst completing his rehabilitation and everybody connected to Hull Kingston Rovers wishes him all the best for a full and speedy recovery.”
The former Bradford Bulls man did not travel when Hull KR’s players flew to Lanzarote yesterday to begin a pre-season training camp.