The talented 21-year-old, who is widely considered to have the best hands at the club, has played just 14 matches in three seasons, but finished 2011 as a permanent fixture.
Cornelius earned his chance following captain Jonathan Brown's second horrific facial injury of the season against Geelong in round 17, and played the final six matches of the year.
He showed glimpses of his talent, including a career-high bag of four goals against Adelaide.
But throughout his time at the Lions, the one knock on the Tasmanian has been his running and ability to apply defensive pressure, and it's something Cornelius has worked to rectify during the pre-season.
Although not the most gifted mover, the 192cm forward has clearly developed that part of his fitness in the past three months.
"I feel I have the ability to play at the level but my fitness has been a hindrance in the past," Cornelius said.
"I've improved all my times this year and I've certainly worked on it a lot more than in previous years. It is mentioned quite often and it does play havoc in the back of your mind a bit.
"I've done a few things off my own bat and I know what to expect now and how to push my body and get the best out of it.
"I'm pushing myself in the drills and the running and surprising myself. In a few running sessions I've been surprised at how well I've gone."
Cornelius said playing the back-end of last season was a significant confidence boost for him after being used sparingly over his first three seasons.
Despite Mitch Clark (Melbourne) and Brent Staker (knee) missing from last year, Cornelius still has to ward off challenges from fellow youngsters Jordan Lisle, Patrick Karnezis, Ryan Lester and Bryce Retzlaff.
"Even without those guys (Clark and Staker), injuries come into play and that's the way I've looked at it previously, but with the way I've handled myself in the pre-season and the way I played the last few games, I'm looking forward to being one of those players that other guys have to take the spot off," he said.
"Hopefully they'll be trying to take my spot off me, that's the way I'm looking at it. I'll try and get in the team early in the year and hold the spot for as long as I can."
Michael Whiting covers Brisbane Lions news for AFL.com.au. Follow him on Twitter: @mike_whiting
