The slumping Giants, who have lost their last three games, will be without small forward Zac Langdon for eight weeks after he underwent surgery on his ankle.

Ruckman Matthew Flynn, who has yet to make his senior debut tore the anterior cruciate ligament in his knee in a NEAFL game last weekend.

The injuries add to an already extensive list, with ace midfielder Stephen Coniglio undergoing knee surgery on Tuesday after he was hurt last weekend.

"He had surgery this morning and had some cartilage taken out so it's been a pretty good result, it looks like about eight weeks," GWS general manager of football Wayne Campbell said.

The Giants are set to face Collingwood on Saturday without their three most accomplished midfielders.

Co-captain Callan Ward-suffered a season-ending ACL injury after playing just one game and Josh Kelly has a calf problem.

Defender Aidan Corr, midfielder Matt de Boer, forward Jon Patton and off-season recruit Tom Sheridan are also currently unavailable, with all bar Corr still at least a few weeks away from returning to action.

One positive on the fitness front is the news that veteran ruckman Shane Mumford will be available this week, after missing two games with soreness.

"He's had that sore knee, sore foot and sore older body but the two weeks off has been good for him," Campbell said.

Highly regarded 20-year-old West Australian Taylor has extended his contact until 2022.

Taylor, who was already contacted for next year, has missed just one game this season and that was due to an injury.

Across Sydney, Swans' stalwart Harry Cunningham will miss Saturday's clash with Fremantle in Perth due to groin soreness.

Ruckman Sam Naismith, who hasn't played since 2017 after suffering an ACL injury early last year, is on track to make a return at some level in round 19.

Australian Associated Press