The workhorse lock is pushing hard to be fit for round one, which would be remarkable given he only ruptured his anterior cruciate ligament against the Warriors in early August.

Fensom has suffered a number of serious injuries in his career, including his bicep, shoulder and elbow, and he's used the last few months to rid himself of niggles he's carried the last few seasons.

Prop David Shillington is more likely to be fit for the season opener against Cronulla after undergoing surgery on the fourth pectoral tear of his career.

It's the first time the former international has gone under the knife to rectify the problem and he's hopeful to be fit for Canberra's second trial match against Newcastle at Seiffert Oval.

Fensom has endured a massive workload since his debut in 2099, and his enforced absence from pre-season contact sessions may be a blessing in disguise.

"It [round one] would be an early return, but I'm confident in the medical staff here," Fensom said.

"I think I'm going to come back stronger than ever before, I've put on a few more kilos and have more speed as well, doing specific drills.

"It's not going to hurt me to miss the contact in pre-season, I do enough of it during games."

He's desperate to be fit for round one after missing the first two games last year with a rib problem.

The 31-year-old's presence would be huge for Canberra after he rediscovered his best form late last year.

"It's my fourth pec tear and the first time I need surgery, which has been a different challenge," he said.

"I got the sling off after six weeks and couldn't even lift my arm off my chest, it was so weak and wasted away.

"I've come from that into full training now and got my bench-press targets back to within 10 per cent of where I was."

Shillington admitted he has work to do to get his confidence back in his body.

"I can handle the collisions at training but I'm not throwing myself into it as much as I normally would," he said.

"I have to build that confidence, and get used to the wear and tear."