GREATER Western Sydney recruit Brett Deledio is facing a battle against time to take the field this season after injuring his other calf at training.

The 30-year-old was eyeing a mid-season return from a lingering right calf injury, however his latest setback casts significant doubt over his availability in 2017.

The club said Deledio had suffered a "grade-one strain" and could not put an accurate time frame on his return at this stage.

However, it described the injury as 'minor'.

Giants assistant coach Dean Brogan confirmed Deledio's injury on Sunday morning.

"Unfortunately for 'Lids', he got out there and did some footy skills at the main session (on Thursday) and looked a million bucks, and then towards the end he tightened up in his left calf," Brogan told Fox Footy.

"It's the other leg now from what I know and it's just a real minor thing, (but) it's going to put him back again.

"I can only imagine what's going through his brain at the moment."

Brogan said the extent of Deledio's left calf setback remained unknown.

"It's frustrating for everyone, not only for him and his family, but all he needs to do is knuckle down and go through it all again," Brogan said.

"It's unfortunate, but I'm not sure how bad it is or where this puts him for the rest of the season."

Giants coach Leon Cameron said it was hard to sugar-coat his star recruit's latest setback. 

"We're not going to hide away from the fact we are disappointed," he told Triple M.

"More for Brett - I mean obviously we've love him playing for us at the moment, but for Brett it's a challenging time for him. It's been a challenging time since around that February mark."

Given Deledio's history, Cameron said regular rules around the relatively minor strain didn't apply. 

"With these injuries you probably think it's a normal one or two week injury, but because he's had repeat calf issues, I can't tell you how long that's going to be," he said.

"We're not going to deny it: it's frustrating for him and frustrating for us.

"I'm confident that we're doing everything right for him...it's just whether his body is going to be able to hold up, that's the million dollar question."

After a near faultless pre-season, Deledio suffered a right calf strain in early February and re-aggravated the injury less than a month later when he was close to resuming full training.

Deledio was restricted to just 11 games in his final year at Richmond due to lingering Achilles and calf problems, with the latter forcing him to miss the Tigers' last six games of the season.

The dual Tigers' best and fairest joined the Giants during last year's NAB AFL Trade Period.