This defeat, somehow, felt even worse for Nathan Buckley.

Buckley's Collingwood lost last year's Grand Final to West Coast via a dramatic and late Dom Sheed match-winner after kicking the first five goals of the game.

On Saturday, the Magpies slotted the last four but still went down by four points in their preliminary final against Greater Western Sydney – after being 33 points down in the final term – to again be left with a hollow feeling.

However, for a visibly shattered Buckley, it was "worse" because of how the match ended, and he went as far as describing the season-ending defeat as "a waste".

"There's a jumble of emotions there. It is quite difficult after a result like that to stand in front of the players and really wrap them up, because we've just lost a game," Buckley told reporters.

"Looking at the last 30 minutes, if we could have found a little extra through the early parts of the game, we could've won it – but we didn't.

"The side that won it deserved to win it, because they were the better team on the night.

"I still have real belief in our playing group and how we go about it, and our coaching group and how we set up players, and the administration of our club and how we carry ourselves.

"All of that is there, and you can't finish at the pointy end of a season without getting a lot of those things right, but there's still a lot of areas we can be better."

The Giants set up victory with a five-goal-to-none third term and went to three-quarter time with a sizeable edge in contested possession (127-101) and clearances (39-26), despite Brodie Grundy's dominance.

Collingwood made up ground in the former (164-148) but wound up losing the clearance tally 54-35.

"Around the ball, we just didn't have sway until the last quarter at all," Buckley said.

"Our pressure was still pretty good and was holding us in it (and) our defensive mechanisms were OK, but they were able to hit the scoreboard in that third quarter through weight of field position.

"In the end, we were minus-20 in clearance. You're not going to win many games with those numbers."

Buckley was circumspect on the umpiring and the three score review decisions, saying he didn't see the controversial Josh Thomas goal in the fourth quarter that looked to have been touched.

He did admit he thought the non-free kick to Grundy, where Jeremy Finlayson pushed him aside in a ruck contest then kicked a crucial third-quarter goal, "looked like a shove in the back".

"This will be the hardest week of our life; watching what's going to take place in the next seven days. And there's no coming back. It's click of the fingers and that's over," Buckley said.

"We didn't make the most of our moment. The guys on this side (GWS) did, so they progress and we don't.

"There were times we could've been cleaner at ground level and times we would have hit more targets, (but) we didn't.

"There were some umpiring decisions that went for us and against us, (and) that's the game, that's life."