Richmond have traded fringe tall Bigoa Nyuon to North Melbourne in exchange for a fourth-round selection for this year's draft.

Nyuon has been strongly linked to Arden Street as the Roos look to add more height to their list following the departures of key-position free agents Ben McKay and Todd Goldstein, who departed for Essendon last week.

The Kangaroos secured access to former Sydney defender and Glenelg talent Toby Pink last Fridau via delisted free agency and have now made a move to secure Nyuon from Punt Road.

Nyuon was eligible to move through last week's free agency period, but a switch to North Melbourne would likely have impacted the Roos' free agency compensation selection of Pick 3 if they had attained a free agent themselves.

Nyuon has now been traded to the Roos in exchange for Pick 65.

"Biggie is an athletic key defender who stood out to us with his ability to take intercept marks and his versatility to play as ruck," North Melbourne list manager Rawlings said in a club statement.

"The Tigers have a few tall options down back and in the ruck, so he's searching for an opportunity to play senior football.

"We look forward to welcoming him into the club and seeing his attributes further develop here."

The Roos move on that fourth-round pick, which was originally Hawthorn's selection and was moved on to North Melbourne from Fremantle last year, to secure the 22-year-old.

Able to play in defence or as a supporting ruckman at the height of 197cm, Nyuon brings with him just one game of senior experience.

He made his debut last year against the Hawks in Round 9 and recorded six disposals and two tackles.

The additional picks now sees the Tigers holding selections 29, 50, 65 and 68 for next month's National Draft.