THE ADDITION of defender Marley Williams to North Melbourne's line-up should ensure small forwards don't dominate the Kangaroos, Jamie Macmillan says. 

North was bundled out in the first week of finals last year after Adelaide superstar Eddie Betts booted six goals in a masterful display. 

Macmillan told RSN on Thursday the club's backline was bolstered after the former Collingwood player was traded in for pick No.105 in the NAB AFL Draft.

"(Williams has) been adding a little bit of run and a little bit of drive. A lot of guys have spoken about our backline perhaps lacking that a little bit. He’s certainly bringing that to the table," Macmillan said. 

"He adds another dimension. He can also lock down, which is something we’ve probably struggled with, just thinking back to the Adelaide final with Eddie Betts kicking five or six (goals).

"To be able to bring in a defender to perhaps take someone like that out of the game will be helpful." 

A foot strain sidelined Williams for five matches last year while he was also dropped twice after inconsistent form.

The 23-year-old finished equal-sixth in the Magpies' best and fairest in 2015. 

Macmillan, who is in the leadership group for a third consecutive year, has been spending time playing on another of the Roos' recruits, Nathan Hrovat.

The 175cm forward was traded in from the Western Bulldogs in a swap of late selections for this year's draft. 

"Geez he's small, that's the first thing I noticed. He's very, very small but he's certainly lively and he put himself in good spots and works hard," Macmillan said. 

"He's got a really good footy brain as well. He's not afraid to let us know his thoughts on different things, and obviously he's come from a really successful club. 

"I expect them (Hrovat and Williams) to both play this year, and probably pretty early as well." 

Macmillan believes the club's first pick from last year, Jy Simpkin, could be headed for great things.

Simpkin has had a limited pre-season after a broken leg suffered last April while playing for his school side, Scotch College, wiped him out for the year. 

"Sometimes with young kids you just get that sense (they could be special). It's weird, but you can just feel something with him," Macmillan said.