Darcy Moore will start Collingwood's season as a 'key back', coach Nathan Buckley has confirmed.

Moore has been training in defence for much of the pre-season, and all signs were pointing towards the positional switch.

"It's a significant decision, but you do have the right to change your mind," Buckley told SEN on Wednesday morning.

"We will have the benefit of exposure and information that will come in the form of practice matches, pre-season games, JLT and early season games," he explained. 

"Darcy has had a little bit of a broken pre-season but when he has trained, he's probably trained about 75 per cent of the pre-season thus far, he's looked exceptional behind the ball.

"We have had him in front of the ball at times.

"We're excited about what he can bring on the field.

"We intend initially to play him as a key back, and he's got his head around that (and is) looking forward to it."

The ruck responsibilities will again fall to Brodie Grundy and Mason Cox who Buckley believes both fit into the Magpies' best 22.

"It'll be a product of how the big boys stand up up front - we do want to play Cox and Grundy in the same side, and feel there's some real strengths that we have on our list in the form of those two big boys that could give us a competitive advantage.

"And of course there's Ben Reid who has shown some signs as a key forward. We know he's got the capacity to go back as much as Darcy has forward so we've got a bit of scope there."

Moore kicked 25 goals in 21 games across his third AFL season. 

"He's not a shrinking violet, he wants to be in the action," Buckley said of the young forward.

"(I) personally have a belief that you really need to build from the back, and it's going to be important for us to win one-on-ones both aerially and on the ground in our back half in order to support our defensive structures and Darcy will be important in that.

Buckley also re-stated his support for captain Scott Pendlebury, insisting there was no doubt about the 30-year-old continuing on as captain.

"Not in my mind no, and not in the minds of his teammates either and that's the crucial aspect of it," he said.

Collingwood's season begins with a Saturday night clash against Hawthorn in round one.