Collingwood tall Mason Cox is set for a fourth year in the black and white as the American has earnt a contract extension via triggering a clause in his contract, per The Age's Michael Gleeson.

Cox will remain on $550,000 for the 2021 season at the Holden Centre after playing a sufficient amount of games with the club in his opening three seasons with Collingwood.

An incentive in Cox's contract to play close to 50 games in his first three seasons would give him the opportunity to play on for a fourth term, with the out-of-favour forward having already played 38 games heading into 2020.

With several games under his belt already this season - added to the proportional ratio for game-based incentives following a reduced season - Cox was able to trigger a spot on Collingwood's list for next year.

The lanky yank played arguably his best match for the season against the Blues on Sunday, giving plenty of opportunities to small forwards in Josh Thomas and Jaidyn Stephenson in the Magpies win.

While he may not be part of Nathan Buckley's preferred 22, Cox will remain in contention for the Magpies selection for a further 12 months at least as he hopes to cement his position as a forward-ruck utility.

Sydney recruit Darcy Cameron has been favoured as the backup to Brodie Grundy in the ruck whilst offering a target going forward, with fellow talls Will Kelly and Brodie Mihocek missing minutes through injury.