BRETT Deledio has been officially ruled out of contention for Greater Western Sydney's season opener against Adelaide after aggravating his troublesome calf injury during the week.

Deledio played just 11 games for Richmond last season due to persistent calf and Achilles issues, and the latest setback is a massive worry for the Giants and the 29-year-old star.

Speaking after the club's JLT Community Series loss to the Swans, GWS coach Leon Cameron revealed that Deledio had been close to getting back onto the field but broke down at training this week.

Giants go down to Swans in the wet

"He had six really good weeks with us then hurt his calf a few weeks back, then he looked like he was going to get going again, but he's re-injured it," he said.

"It's disappointing for him, it's always hard when you're a new player from another club that wants to get out there and impress.

"He just wants to get out there and play, as a professional athlete, so it was disappointing to cop that news during the week."

Deledio was always going to struggle to prove his fitness for the Giants' first game of the season against the Crows after hurting his calf in early February.

He still hadn't joined the main training group on a full-time basis, instead limited to some running exercises and gym work, but Cameron said he has faith the club's rehabilitation experts can work their magic on the former Tiger.

"I'm confident that our medical staff are doing all the right things.

“Yes, over the last two years he's had setbacks in terms of his Achilles, calves and quads, but I'm confident they can get him right," he said. 

"It's about finding out what he can and can't do at this stage, but we're confident that he can get up and running and play some good footy for us."

Cameron said the Giants wouldn't be looking at placing Deledio on the long-term injury list.

"Right now we've got a full book other than a couple of injuries; Brett is one of them and Matt de Boer (hamstring) is the other, that aren't available to play round one," Cameron said.