KARL Brown was not fit enough last year and he knew it.

Despite attracting the attention of AFL clubs in 2015, the young Calder Cannons forward struggled to transition from one end of the ground to the other and his lack of fitness ended up costing him.

So the 18-year-old – who will start as Vic Metro's lynchpin in attack against Vic Country in the NAB AFL Under-18 Championships at Simonds Stadium on Monday – decided to do something about it.

After a meeting with his parents, Cannons talent manager Ian Kyte and strength and conditioning coach Todd Beames in September last year, Brown – who returned to Calder as a 19-year-old player after being overlooked in last year's draft – decided to enroll in the Elite Athlete Performance network program.

Based in Swan St, Richmond, the program owned by Vic Metro physical preparation manager Damien Villarosa, is designed to prepare young athletes for elite level sport, tracking their training habits, strength work, recovery and nutrition.

"It was a small hint of an AFL environment and I can push my body further than I have ever done now," Brown said, reflecting on his time in the program.

The gruelling bike sessions inside an altitude chamber and a specific focus on leg strengthening exercises in his time in the program, on top of the three days a week training with Calder, had Brown primed to attack the start of 2016 with gusto.

"He was coming in five days a week for either strength work, conditioning or recovery, even through January, when most kids are happy to be sitting at the beach," Villarosa said.

The hard work paid off as the 193cm and 91kg key forward took the TAC Cup by storm, kicking 27 goals in Calder's opening nine games (including bags of nine and six in successive weeks) of the season.

"We can't make anyone go and do the work and no doubt early on he hurt, but he worked his way through it and he's a better player now because of that," Villarosa said.

Brown's improved fitness and his enhanced mobility helped him get to more contests where he could use his contested marking ability to greater advantage.

Brown's ability to out-jostle his opponent in a marking contest and take the ball cleanly at pace on the lead are identifiable traits. That he can bomb long-range goals creates further excitement about his future prospects.

Those attributes certainly caught the attention of the Vic Metro selectors who added Brown to the squad, knowing there was a dearth of tall forward options around the country.

The fact that Brown missed out on representing Metro in last year's Under-18 Championships after injuring the meniscus in his knee in April, gives him extra motivation to perform well on Monday.

"I've always wanted to play for Victoria and I can't wait to get out there and hopefully we prove we're going to be a really good, tough side this year," Brown said.

"It's going to be a big step up but I can't wait for the challenge."

The under-18 carnival presents an opportunity for Brown to step up and prove he has the ability and the temperament required of an AFL prospect.

Brown believes the training program he completed in the off-season has him well prepared if he gets the chance to step into an AFL environment at the end of the year.

"If everything goes right and I am lucky enough to go to an AFL club then I've got a nice base of what to expect when I raise my training to the next level," Brown said.