Israel Dagg is facing a difficult decision on his playing future.

With the Super Rugby season starting next weekend, the Crusaders outside back is again battling knee injuries and reduced to a spectator in training.

Coach Scott Robertson said Dagg was working closely with the medical team but a return date is still unknown.

"We're still going through a lot of tests with him around his knee and getting the best possible outcome ... [and whether] he's involved in the next few weeks or if they take other measures," Robertson said at the Crusaders' Waitangi Day training session.

Advertisement

"He's working closely with the medical group to make a decision on what's best for him in the next few months."

Dagg has been no stranger to injuries, and has particularly struggled with his right knee which he reinjured in April last year after a long recovery which included stem cell therapy.

The 30-year-old now faces a tough decision about what's best for the longevity of his game and career, with another surgery a very real possibility.

"It could [require an operation]," said Robertson. "That's the thing, how big that operation is and there's a lot of factors of what it will look like.

"And if they do operate, is it now or later? Or does it give him longevity in the game? He's got some big decisions to make."