The reliable backman, who has missed just one game this season, aggravated his back during Friday’s training session at Olympic Park.
Toovey’s place in the squad has been filled by Tony Armstrong, who is averaging 17.2 disposals, 2.2 inside 50s and 2.2 rebound 50s in the VFL this season.
Armstrong arrived at the Westpac Centre as a delisted free agent last November after stints with Sydney and Adelaide.
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Star forwards Ben Reid and Jamie Elliott slot back into Sunday’s side, as do key backman Lachlan Keeffe and young onballers Tim Broomhead and Kyle Martin.
Josh Thomas has been omitted from the extended 25-man squad that was named on Thursday night.
He will join the retired Nick Maxwell and injured trio Dane Swan (foot), Luke Ball (back) and Toovey on the sidelines.
Thomas, Armstrong and Sam Dwyer are the team’s three emergencies.
As a result of the five changes to the side, the Magpies will field six players with less than 25 matches of senior experience, 11 without 50 games and 11 under the age of 23.
It ensures the team will take on a fresh look, particularly given the return of Ben Reid, who will play his first home and away match of 2014.
Collingwood v Adelaide
Round 18
Sunday 27 July
MCG, 4.40pm
Collingwood
B: Marley Williams, Jack Frost, Taylor Adams
HB: Paul Seedsman, Lachlan Keeffe, Heritier Lumumba
C: Steele Sidebottom, Brent Macaffer, Tim Broomhead
HF: Kyle Martin, Jesse White, Ben Kennedy
F: Jamie Elliott, Travis Cloke, Ben Reid
Foll: Jarrod Witts, Dayne Beams, Scott Pendlebury
Int: Tyson Goldsack, Jarryd Blair, Tom Langdon, Clinton Young
Emg: Josh Thomas, Sam Dwyer, Tony Armstrong
IN: Tim Broomhead, Jamie Elliott, Lachlan Keeffe, Kyle Martin, Ben Reid
OUT: Nick Maxwell (retired), Luke Ball (back), Dane Swan (foot), Alan Toovey (back), Josh Thomas (omitted)
