GREATER Western Sydney has suffered a massive blow ahead of its clash with the Western Bulldogs on Saturday afternoon with No. 1 ruckman Shane Mumford a late withdrawal with general soreness.

Mumford has been replaced by key-position player Adam Tomlinson, with Jonathan Giles now set to carry the Giants' ruck division as its tackles the Bulldogs' All Australian ruckman Will Minson.

Mumford joined the Giants in last year's trade period from the Sydney Swans and has been one of their most influential players in the first three rounds.

The former Swan led the AFL in hit-outs after round three with 151, and had 60 in the Giants' win against Melbourne last Sunday.