A gutted Hyne could miss most of the 2018 campaign after scans confirmed he had damaged his medial ligament and anterior cruciate ligament.

The luckless 23-year-old will meet surgeons in the coming week to determine a rehabilitation process and create a clearer timeframe for his comeback.

Hyne could be ruled out for up to nine months depending on the extent of the damage and the reconstruction options.

A nine-month recovery would make him unavailable for all but two of the Brumbies' regular-season games next year in a shattering twist to the one-year contract extension he signed less than a month ago.

The good news is the Brumbies have already shown they are willing to put faith in injured players after the club re-signed Lausii Taliauli, despite the winger missing the entire 2017 season.

"I just wanted to put [Hyne's] mind at ease. The first thing guys do is worry about contracts and that sort of thing," McKellar said.

"Don't stress about that. We'll see what the results are and get stuck into rehab. We won't be discarding him just off the back of picking up an injury.

"The same thing happened with Lausii and we re-signed him. You don't see loyalty that much in professional sport these days, but at the Brumbies we look after our people.

"Nothing is guaranteed, but Hyney has been in our program for a few years, his character traits fit what we look for in a Brumbies player. So we'll make sure we look after him and then move forward when we know more."

McKellar backed Brumbies rehabilitation gurus Ben Serpell and Byron Field to help Hyne's transition back into rugby after medical staff settle on a surgery plan.

Taliauli is set to make his rugby comeback in the coming weeks after injuring his knee in January, while Serpell and Field have also helped David Pocock and Stephen Moore recover from knee reconstructions.

Hyne's absence will leave a big hole in the Brumbies' squad given he is capable of covering at No. 8 and blindside flanker.

But the recruitment of former Western Force star Isi Naisarani and the arrival of Lachie McCaffrey will give the Brumbies ample back-row coverage.

Pocock will be back in Canberra after taking a 12-month sabbatical, while Olympian Tom Cusack, Lolo Fakaosilea and young gun Rob Valetini will also be chasing game time next year.

The Brumbies have the option of adding a supplementary player to their roster to cover Hyne's injury, but McKellar is putting faith in squad depth to fill the gaps.

"This is a setback. But Hyney has all the qualities to make sure he bounces back," McKellar said.

"You've got to remain optimistic. He's done the hard graft moving down to Canberra when he didn't have a contract and then through performance, earnt a spot at the Brumbies.

"We won't go down the path of looking at extra players in the short term. We've got players to cover the back row, but if we need some coverage down the track that's something we can look at."

The Brumbies are expected to add two more back-line players to their roster before the squad starts pre-season training in November.

Taliauli will use the Canberra Vikings and National Rugby Championship to launch his rugby comeback plans, with the former Gold Coast Titan edging closer to playing again.