Cerra's move is the biggest deal of the trade period so far, with the midfielder's transfer to Ikon Park completed on his 22nd birthday.

As well as Carlton's first-round draft pick, Fremantle get a future third-round selection for giving up Cerra.

Taken by Fremantle with pick five in the 2017 draft, Cerra has played 76 games and finished third in the Dockers' best-and-fairest last year.

But the lure of returning home to Victoria was too strong and Cerra rejected the Dockers' offer to stay in Perth.

"We've had the clear intention this off-season to improve our midfield group and with Adam, we're welcoming a real classy on-baller whose best football is still to come," Carlton list manager Nick Austin said.

"... With the addition of Adam, as well as George Hewett as a free agent, we think we've bolstered our midfield mix and really complemented our current playing list heading into the 2022 season."

The Blues later completed a three-way deal to secure Western Bulldogs tall Lewis Young, with former No.6 draft pick Sam Petrevski-Seton heading to West Coast and the Bulldogs receiving the Eagles' pick No.52.

Petrevski-Seton returns to Western Australia after 94 games for Carlton, while Young made 24 appearances for the Bulldogs, most recently as a ruckman - though he is expected to be a defender at the Blues.

Earlier on Thursday, Gold Coast traded picks No.19, 61, 69 and Will Brodie to Fremantle for the Dockers' future second and fourth-round picks.

Gold Coast had been keen to offload Brodie's salary and open up a list spot, while they have also been stocking up on 2022 draft picks.

A tough on-baller, Brodie has played just 25 AFL games across five seasons since he was drafted at pick No.9 in the 2016 AFL draft and will get a fresh start in Fremantle's midfield.

The Dockers also sent pick No.27 and a future third-round pick to Collingwood for pick No.22.

Either Pick No.19 or No.22 could head Geelong's way as part of a deal for contracted speedster Jordan Clark.

Meanwhile the Bulldogs have landed versatile Hawthorn tall Tim O'Brien as an unrestricted free agent on a two-year deal.

O'Brien, 27, played 97 games for the Hawks across eight seasons booting 73 goals, but the Bulldogs plan to use him as a defender.

Australian Associated Press