PREMIERSHIP ruckman Mark Seaby officially became a Sydney Swan and Amon Buchanan a Brisbane Lion after the second deal of trade week was confirmed.

In a complex exchange, the Lions gave the Swans their second-round selection (No.28 overall) for Buchanan while the Swans sent their second-round pick (22) to the Eagles.

West Coast utility Brent Staker and Lions midfielder Bradd Dalziell swapped camps, with Staker also accompanied by the Eagles' third-round draft selection (39).

Swans coach Paul Roos confirmed on Monday morning that Buchanan, who played 116 games for the club since his 2002 debut, would be moving north as Seaby was welcomed to the harbour city.

"It's a good opportunity for him (Buchanan). We had some discussion with him at the end of the year – both us and Amon were undecided – should he stay at Sydney or should he go," Roos said.

"He's a premiership player and a fantastic player, but probably his past couple of years he's been battling a little bit."

Seaby has played 102 AFL games since West Coast selected him at No.22 in the 2001 national draft.