GREATER Western Sydney's key defensive stocks have taken another blow with news that Aidan Corr could miss up to a month with an ankle injury.

Corr left the ground after hurting his left ankle in the opening term of last week's loss to the Sydney Swans, but after treatment from GWS medical staff, he returned after quarter-time and played out the rest of the match.

The 21-year-old was one of the Giants' better players in the 25-point defeat, but scans have confirmed Corr suffered a deltoid ligament strain.

It's the same injury – although less significant – that ended star ruckman Shane Mumford's season last year.

Corr joins teenager Caleb Marchbank (ankle) on the sidelines after he was injured in round two against Geelong and is expected to miss at least another 5-6 games.

The loss of the pair means Nick Haynes could be included to face Port Adelaide on Sunday to give the Giants another tall defender to work alongside co-captain Phil Davis and this week's 200-gamer Joel Patfull.

Haynes had surgery on his groin in December and is close to full fitness after playing the last three games in the NEAFL, and although he wasn't expected to return to the senior side for another week or two, coach Leon Cameron might have no choice but to recall the 22-year-old for the crucial clash with the Power.

Medium-sized backman Matt Buntine is also a chance to face Port after he was a late withdrawal last week with hamstring tightness.