Brodie Grundy is being honest about his stance as Collingwood's first choice ruckman as he approaches his 50th AFL game.

It has been a slow burn for the Collingwood ruckman, pick No.18 in the 2012 NAB AFL Draft, as he has looked to establish himself as the Magpies' main  big man in four seasons on the club's list.

"I've been in the system four years now and I thought my actual ruck craft might have been better than where it is right now," Grundy told AFL Media.

"But over the last four years my body's really developed, my fitness base has really developed and my game knowledge has as well.

"My ruck craft will come as a I develop a bit more of a mature body.

"It's that competitiveness and follow up work that is the cornerstone of my game."

Grundy's ability to accept a challenge was on display as he rucked almost one-out against the dynamic Geelong combination of Zac Smith and Rhys Stanley at the MCG on Saturday.

Not only did he quell the duo's influence, Grundy also had 20 disposals, 13 hit-outs and kicked two goals to be one of the Magpies' best in their 24-point season-saving win.

Grundy's gritty performance came a week after his best game for the year against the Brisbane Lions, following an up and down start to the season.

Although Grundy has demonstrated signs that he is going to be a very good AFL player, coach Nathan Buckley said the 22-year-old was still a work in progress.

"He's still learning what it means to be a hard-edged professional at this level and still be himself and bring elements of his strengths to the table whilst gritting his teeth when things aren't going his way," Buckley said.

One of the things that has held back Grundy's growth has been his propensity to give away free kicks when he is competing in the ruck.

Leading into this round, the Collingwood ruckman had given away 12 free kicks, the highest tally in the AFL. He had also received 10 free kicks.

Grundy said it was a technique issue.

"It's a bit of a touchy subject for me. Yeah, man it's annoying. It is frustrating. But it's about my technique," Grundy said.

Grundy delivered the game's defining moment in the final quarter against the Cats as he got on the end of a coast-to-coast goal that started with a kick-in from Jeremy Howe.

Running into an open goal, the ruckman bounced the ball through, narrowly avoiding the goal post, to clinch the match for the Magpies.

"Everyone craps on about if you're there (running into goal) kick a drop punt versus the dribbler. I was confident with the dribbler and I was just speaking to my family and they said it just went in.

"I thought it was OK and didn't realise how close it came. I'm glad it went through."