Behind the biggest smile in Brisbane's team was a young man not enjoying his footy.

Halfway through his second season, 2017's No.1 draft pick Cam Rayner was struggling for form, and almost dropped from the surging Lions' senior team. 

But with the steadfast support of one of his biggest fans – coach Chris Fagan – the 19-year-old has slowly turned things around. 

On Sunday at the MCG against Richmond, Rayner teased to have a huge impact, but missed a couple of shots at goal after some powerful pack marking.

The fact he had eight tackles – the most of his 44-game career – was a sign of his development and hunger to improve, though.

After the rollercoaster ride of his second season, the man his teammates call 'Pumbaa' now wants to repay the faith shown in him with a big impact in September.

Speaking with AFL.com.au, Rayner conceded it had been a "frustrating" year.

"You're not stupid, you see the stuff in the media everywhere," he said. 

"You've got to come back to what you did when you first started playing footy … it's something I love to do. 

"I worked hard with my coaches and I worked hard with the boys to try and make sure I could get back to enjoying my footy. 

"There was probably a three or four-week patch there where I wasn't, but now I'm back and really enjoying it and doing whatever I can for the team."

Rayner said it was hard to believe only two years ago he was running around for Penleigh and Essendon Grammar School and the Western Jets, and now he was about to play finals in front of packed stadiums.

He's fitted in seamlessly since heading to Brisbane shortly after his 18th birthday, extending his contract by two years shortly after arriving and now lives with his great mate Alex Witherden.

While his first season involved semi-regular stints in the midfield, Rayner has played almost exclusively as a half-forward this year following the off-season acquisitions of Lachie Neale and Jarryd Lyons.

It's a role that has taken some adjusting to, but one he has improved at with the help of another new Lion, Lincoln McCarthy.

Among the changes, there's been one constant for Rayner – Fagan.

"He's the most genuine bloke you'll ever meet, and he's got a great balance between coach and friend," Rayner said. 

"I'm lucky I've got a great relationship with him, like all of the boys do.

"Me and him are pretty close. I can speak to him about most things.

"He was a big help for me when I was going through that tough patch, he was doing extra sessions with me out on the ground, ground balls, making sure I made my possessions count.

"He knew playing this role I wasn't going to get 20 or 30 touches, but just that when I got them I make sure I use them.

"He's been awesome for me, I can't thank him enough.

"The faith he had to keep me in the team when I was going through that rough patch, I feel like I owe it to him to give him something back at the end of the year."