Whilst Gruzewski is yet to debut, he has performed strongly in all three VFL games this season.
Gruzewski's standout game was in Round 2, kicking four goals and taking nine marks, as well as kicking two goals in Round 3.
GWS' General Manager of Football, Jason McCartney praised Gruzewski's efforts this year.
"After a minor setback at the beginning of pre-season, he's returned to the field and showed the skills and attributes that we drafted him for- he has strong aerial abilities, is a great contested mark and can kick goals."
"We have a great group of young players coming through and it's fantastic to secure Max's signature until at least the end of 2026."
Gruzewski stands at 192cm and can play at both ends of the ground, however has been playing as a forward this year.