St Kilda have signed three-time All-Australian Dan Hannebery from Sydney.
The trade sees the Swans receive two second-round picks at the AFL Draft in return for Hannebery, who has inked a five-year deal with Alan Richardson's side.
The Saints have given up pick No. 39 and their future second-round selection to get him, with Sydney also sending pick No.28 to them as part of the trade.
Hannebery had three years remaining on his contract with the Swans but they had indicated they were prepared to let him go if the right trade could be obtained.
He managed only 15 games last season for Sydney and has been affected by injuries over the past two years.
Groin issues have caused his biggest setbacks but he's also had calf problems and Saints have admitted they have carried out a thorough medical on him.
St Kilda head of football Simon Lethlean said: "Our medical staff were very confident that any issues Dan has had this year wouldn't be a problem going forward.
"He hasn't had a pre-season for the last couple of years and he's got some improvement that our guys think they can make through his groins and his posture and other areas he's started working on based on their advice.
"They're really confident he's got a lot of footy ahead of him otherwise we wouldn't have offered the deal we have, or seeking the trade we achieved."
Hannebery had nominated the Saints as his preferred new home last month, and is set to earn $800,000 a season over his first four years with the club.
St Kilda have also signed Melbourne forward Dean Kent on a three-year deal.
They will give up pick No.65 to the Demons for the 24-year-old, who has kicked 63 goals in 63 games for Melbourne.
St Kilda are 80/1 to win the 2019 Grand Final.
St Kilda's Tim Membrey is 80/1 to win the Coleman Medal.
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