GWS will be without gun ball-winner Tim Taranto for Saturday's match against Essendon, having experienced concussion symptoms late into the week.
The Giants confirmed on Friday that after further assessment Taranto would be ruled out of Round 21, despite being cleared by club doctors earlier in the week.
Taranto is understood to have trained throughout the week, however faced worrying signs on Friday.
The Giants have since made the decision to remove Taranto from their squad to face the Bombers, with Lachie Ash coming into Mark McVeigh's lineup.
Ash's reprieve comes after Stephen Coniglio, Jake Riccardi and Kieren Briggs were named as inclusions for Round 21.
Forward Xavier O'Halloran has been added to the club's emergencies for the match after being omitted from last week's squad.
Cameron Fleeton, Callum Brown and Tanner Bruhn are also listed as emergencies.
Saturday's match will take place at GIANTS Stadium at 2:10pm (AEDT).