DELISTED Lion Zac O'Brien hopes a career-high fitness base and the removal of the substitute in 2016 sees him earn a second chance.

Despite winning the Lions' reserves best and fairest and playing eight AFL games in 2015, he admits he was "a little shocked" when told Monday he was to be cut.

As the AFL removes the green vest and drops the interchange cap to 90 next year, O'Brien has only ramped up his fitness training.

"Fitness has never been an issue for me at AFL level, I've trained with guys like Dayne (Beams) and Tom (Rockliff) day in day out and been able to compete," he told afl.com.au. 

"I've been on a surfing trip but been running and in the gym, I’m just hungry to get a second chance whether that's in the rookie or pre-season draft."

"I think my two year's experience in the competition puts me in front of others looking for that opportunity and hope a club sees that as an advantage.

"I've built up that mental strength of preparing for games for two years in and out of the side."

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The 24-year-old reached the headlines in May when he was involved in a physical altercation with coach Justin Leppitsch, but he has moved on. 

"Even after the incident I played good consistent footy," he said. 

O’Brien starred at local level in his teens, before finding his way to Essendon VFL in 2013 and recruited to the Lions where he spent two years, putting on hold a chiropractic degree he spent half a decade earning. 

After dominating games in the NEAFL, including a 52-disposal match against the Swans in August this year, seven of his 13 AFL matches were spent in the vest. 

From eight games this year, he was ranked the ninth most effective centre clearance player in the competition. The Lions calculated an 18 per cent differential winning the clearances based on his presence at the centre bounce. 

O’Brien topped the reserves leaderboard with 55 votes, an incredible 34 more than runner-up Rohan Bewick, who was this week re-contracted by the Lions.