Former Port Adelaide star Kane Cornes believes Collingwood made a mistake in bringing big man Mason Cox back into the side for Friday night's clash against GWS.

Coming off a dominant 44-point win over St Kilda last week, key forward/ruckman Darcy Cameron was omitted in favour of Cox at this week's selection table.

Speaking on SEN’s The Captain’s Run, Cornes believes the inclusion of the American could upset the chemistry of a Pies forward line that was firing on cylinders against the Saints.

“Collingwood welcome back the big American Mason Cox for tonight’s game against the Giants in Sydney,” Cornes said on SEN’s The Captain’s Run.

“Unfortunately though for the Pies it’s a selection mistake.

“They don’t need him and it threatens to disrupt the electric chemistry the Pies forwards had against the Saints last week.

“The unpredictable entries had St Kilda’s defence guessing (last weekend) and nervous and with Cox coming back into the front six, he’ll automatically draw the ball and risk the side becoming predictable as they have in the past when the big seven-footer has played."

Cornes praised Collingwood's mix of mobile forwards and believes they already had the perfect balance.

“Collingwood have a prototype forward mix," he added.

“Brody Mihocek is the key target who does the grunt work and heavy lifting. The brilliant Jordan de Goey who also plays tall. Then you surround them with speed, pressure and brilliance. (Jaidyn) Stephenson, (Jamie) Elliott, the ever-improving (Josh) Daicos and Browns (Tyler and Callum).

“It’s a nightmare for the opposition.

“The selection of Mason Cox threatens to derail the chemistry at the Magpies. I wouldn’t have picked him.”

Cox booted two goals in Collingwood's emphatic 52-point win over the Bulldogs in Round 1 before suffering a knee injury during the league shutdown.

Cameron filled his role admirably in the club's Round 2 draw with Richmond, tallying 13 disposals and taking eight marks.

The Pies meet the Giants tonight at Giants Stadium at 7.50pm (AEST).