The Magpies have lost four stars to injury with Dale Thomas (hamstring), Heath Shaw (hamstring), Ben Reid (quad) and Luke Ball (knee) all out of the side that lost to Carlton last Friday night at the MCG.
Ruckman Cameron Wood, who played his first game of the season last weekend, is omitted.
Veteran defender Ben Johnson will play his first game of 2012 and adds experience to a side missing a host of big-name players.
Youngsters Paul Seedsman and Jackson Paine, who both debuted in round one and played the first two matches of the season, have been recalled along with Simon Buckley and Tom Young, who will both play their first AFL games of the year.
Nathan Brown, Cameron Wood and Kirk Ugle are the Magpies’ three emergencies.
Click here to read Saturday's ultimate match preview.
Johnson, who recently turned 31, has played 224 league matches, the last of which came in the 2011 Grand Final. He has played the first three matches of the VFL Magpies’ season after recovering from a hamstring injury sustained in February.
20-year-old Seedsman, who started as substitute in both his appearances, played in the VFL team last week and is a versatile 189-centimetre flanker/wingman who was drafted with the 76th overall pick in the 2010 AFL Draft.
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Paine, a robust 191-centimetre key-position player, kicked a goal in each of his senior outings and was impressive at VFL level last week. The 18-year-old was picked by the club at No.50 overall at the end of last year.
Long-kicking defender Buckley has played 34 matches, including 13 for the Magpies last year. He started his career at Melbourne where he played 21 matches in three seasons from 2007-09.
View the match day and ticketing details here.
Young gets his first crack of season 2012 after making his debut last year playing two matches. Once listed on the NSW scholarship list, the 19-year-old gathered 24 disposals in the VFL win last weekend.
Port Adelaide has made three changes with John Butcher (5 games, 13 goals), Brent Renouf (52 games, 9 goals) and Darren Pfeiffer (7 games, 4 goals) named to replace Matt Thomas, Jarrad Redden and Cameron O'Shea.
The Magpies will have a four-day break after Saturday’s match leading into Wednesday’s ANZAC Day blockbuster against Essendon at the MCG.
Click here for the Magpies' full injury list.
Collingwood v Port Adelaide
Saturday 21 April
Docklands, 2.10pm
Collingwood
B: Harry O’Brien, Lachlan Keeffe, Ben Johnson
HB: Simon Buckley, Nick Maxwell, Tyson Goldsack
C: Dane Swan, Tom Young, Sharrod Wellingham
HF: Jackson Paine, Chris Dawes, Ben Sinclair
F: Dayne Beams, Travis Cloke, Alex Fasolo
Foll: Darren Jolly, Scott Pendlebury, Steele Sidebottom
Int: Martin Clarke, Jarryd Blair, Alan Toovey, Paul Seedsman
Emg: Nathan Brown, Cameron Wood, Kirk Ugle
In: Ben Johnson, Simon Buckley, Jackson Paine, Paul Seedsman, Tom Young
Out: Luke Ball (knee), Ben Reid (quad), Dale Thomas (hamstring), Heath Shaw (hamstring), Cameron Wood (omitted)
Port Adelaide
B: Jacob Surjan, Alipate Carlile, Jackson Trengove
HB: Ben Jacobs, Troy Chaplin, Danyle Pearce
C: Hamish Hartlett, Dominic Cassisi, Kane Cornes
HF: Travis Boak, Justin Westhoff, Robert Gray
F: John Butcher, Jay Schultz, Chad Wingard
Foll: Brent Renouf, Bradley Ebert, John McCarthy
Int: Paul Stewart, Matthew Broadbent, Daniel Stewart, Darren Pfeiffer
Emg: Matt Thomas, Simon Phillips, Aaron Young
In: John Butcher, Brent Renouf, Darren Pfeiffer
Out: Matt Thomas, Jarrad Redden (rested), Cameron O'Shea
New: Brent Renouf (Hawthorn), Darren Pfeiffer
