Riley Hardeman admits it might take a while to convert his grandmother - "a die-hard, one-eyed Saints fan" - to North Melbourne. 

The Swan Districts product was selected with pick No.23, the Roos' fifth first-round selection on Monday night. 

The 18-year-old said he had "absolutely no idea the club was interested in him, but he was ecstatic to realise his AFL dream.

"It's something that I’ve been striving for pretty much all of my childhood, all my life," Hardeman told The West Australian. 

"It's the culmination of all my hard work and dedication that has got me to where I want to be. I’m just over the moon. 

"It fits nicely, the North Melbourne jumper. I've got boys like Harry Sheezel messaging me and it's so surreal. 

"I had a Facetime call from Clarko and it’s the fabled Alastair Clarkson that you only see on the TV winning premierships. 

"I'm just so keen to get to the club and get to work."

Hardeman, who captained WA in the U18 Championships, said it was daunting waiting for his turn.

"Pick after pick after pick where my name wasn’t being called out. It was starting to get a bit daunting," he said.

"It was just a sweet wash of relief as my name got caught out. It's really unique having your name called out, nothing like that is ever going to happen in your lifetime.

"It was pretty awesome."

Hardeman credited the "profound" impact his family has had on him, including mum Andrea and dad Andy, as well as younger brothers Josh and Christian.

But while his immediate family had already donned the Roos’ blue and white, how long with it take his grandmother to come around?

"I couldn’t tell ya," Hardeman admitted. "As long as it wasn’t Fremantle, she just doesn't like purple so I'm sure she'll come around."