GIANTS captain Stephen Coniglio could face an extended period on the sidelines after a nasty ankle injury during the club's 34-point loss to Melbourne on Sunday night.

And the news could get even worse for the GIANTS, who also finished the game with key defender Phil Davis and tagger Matt de Boer on the bench.

The GIANTS fell to 0-3 to start to the season after being outplayed and outgunned by Melbourne at Manuka Oval.

Coniglio was in obvious discomfort after being tackled by Tom Sparrow in the second quarter, with coach Leon Cameron revealing his captain was unable to put weight on the affected ankle.

"He had a couple (of syndesmosis ankle injuries) a few years ago that were quite nasty. This one didn't look good," Cameron said.

"Cogs is emotional and it's an emotional game, because you don't like to see your captain go down.

"I feel for him. He's had a tough 12 months, but he was on the way back and copped this.

"In true Coniglio fashion, he'll bounce back."

Davis limped off in the second quarter and played no further part in the match, while de Boer, who curbed the influence of Clayton Oliver in the opening half, tweaked his hamstring in the third quarter.

Cameron added it is too early to speculate how much football the three injured leaders will miss.

It adds to a worrying injury list that already includes the likes of Lachie Whitfield, Jessie Hogan, Adam Kennedy and Braydon Preuss.

The Demons conceded three of the opening four goals of the game before running away with a 15.12 (102) to 11.2 (68) victory.

The effort, intensity and competitiveness of the GIANTS could not be questioned, especially compared to their preceding woeful loss to Fremantle in Perth.

But Cameron's side risks hitting crisis point soon if it fails to upset Collingwood in a must-win MCG match on Saturday night.

"I'm really proud of them. They played a tough brand of footy, but probably ran out of legs in the end," Cameron said.

"We're not here to say woe is me and we've got a fair few injuries.

"That's life, you dig in."