AFTER a year out of the AFL, Cam O'Shea appreciates how fortunate he is to be offered a second chance by Carlton.

O'Shea told AFL.com.au he did not take playing in the AFL for granted in his six seasons with Port Adelaide. But when he was delisted at the end of 2016 after 81 games with the Power, O'Shea soon gained some perspective on just how good life was inside the AFL bubble.

After toying with a move into local football that would almost certainly have ended any prospects of an AFL return, O'Shea signed on with the Northern Blues.

The former Eastern Ranges player had already been told by Carlton coach Brendon Bolton and list manager Stephen Silvagni that if he performed well enough with their VFL affiliate he could start the 2018 pre-season with the Blues.

But before that could happen O'Shea would get a taste of life in the real world, working at Nike's Melbourne head office in between his training and playing commitments with the Northern Blues. Working in logistics and as a shop assistant, O'Shea realised just how good he had had it at Port.

"Working does put things in perspective and obviously I won't take it for granted the second time around," O'Shea said from Carlton's pre-season training camp at Maroochydore on Queensland's Sunshine Coast.

"I'll just do everything I can to hopefully string a few games together and pursue my career.

"You just don't really understand how good of a job playing AFL is until it's over. Just being out of the game for a year you can definitely tell that it's a great privilege to be able to play AFL."

O'Shea gave Carlton little choice but to grant him the promised 2018 pre-season after he won the Northern Blues' 2017 best and fairest award and selection in the VFL's team of the year.

He had felt his best chance of joining Carlton would be in the NAB AFL Rookie Draft. But on the morning of that draft, the Blues decided they would use a pick in the pre-season draft – they were the only club to do so – and it was O'Shea's name they called out.

Carlton's decision to add the 193cm defender to its primary list came two weeks after 2017 All Australian defender Sam Docherty ruptured his left anterior cruciate ligament at training.

O'Shea shapes as one of the Blues' possible replacements for Docherty given he's a strong runner and an outstanding intercept mark.

The 25-year-old is understandably reluctant to push his case to replace Docherty – he says his only focus for now is completing a full pre-season – but is confident Carlton can cover the leadership group member's absence in 2018.

"Sam is a massive loss for the group and you can just see his character. The last couple of days he's been out on the track, fulfilling more of a coaching role and just doing everything he can to help out," O'Shea said.

"He does leave a massive hole down there but it provides some opportunity for the guys to step up and I'm sure someone will."

O'Shea has quickly created a good impression with his new teammates. Senior forward Matthew Wright is one who has been taken by his burning desire to play AFL football.

"He's desperate to play some senior footy. He spent a year away with our affiliate side, the Northern Blues, and then to get a second chance, he's hungry to play footy," Wright said.