Collingwood defender Mark Keane in action against Fremantle on his AFL debut in round nine, 2020. Picture: Getty Images

ADELAIDE has signed former Collingwood defender Mark Keane to fill the final spot on its list for this season.

The Irishman spent three seasons on the Magpies' list as a Category B rookie from 2019 to 2021, before returning home in August 2021. He returned briefly for pre-season training in November, but opted to retire from the game after five senior appearances.

However, the 22-year-old revealed in May that he'd be open to returning to the AFL.

Mark Keane after the Pies' loss to Gold Coast in round seven, 2021. Picture: AFL Photos

Keane has signed a one-year deal with the Crows during the pre-season supplemental signing period and is expected to join his new teammates at training in coming weeks.

Keane, who stands 194cm and 96kg, said the timing was right for him to return to Australia and he was excited about resuming his AFL career with Adelaide.

"I never lost the passion to play the sport and when the opportunity arose to come back it was something I obviously considered very strongly," Keane said.

"The circumstances are right and so is the timing on the back of winning an All Ireland Grand Final with my club Ballygiblin.

"I will be able to have my family and friends fly out and visit which will make a big difference and I’ll also have the support of my partner Caoimha who will be moving to Adelaide as well so we are very excited about what lies ahead."

Keane has also played top-level hurling and Gaelic football in Ireland.

Mark Keane in action for Cork hurlers. Picture: @skysportsgaa twitter

Adelaide list manager Justin Reid said Keane would help boost the team's defensive stocks this year.

"We are very excited that Mark has decided to return to Australia and committed to continuing his AFL career with us," Reid said.

"We understand the travel and quarantine challenges he faced during the Covid pandemic throughout 2020 and 2021, but thankfully a lot has changed in that space since then.

"Throughout our discussions with Mark and his management he has made it clear he is eager to pursue an AFL career with the support of his family and friends and we are delighted that will be with our club.

"Mark is super competitive, with good speed and lateral movement which we think will complement our young and developing backline nicely."

Players signed during the SSP (Dec 5 to Feb 15)

Liam Shiels - North Melbourne
Oskar Baker - Western Bulldogs
Conor McKenna - Brisbane
Jed Anderson - Gold Coast
Tyler Brown - Adelaide
Liam Stocker - St Kilda
Mark Keane - Adelaide
Darragh Joyce - Brisbane