CARLTON coach Michael Voss has defended the Blues' decision to make six changes ahead of their elimination final and declared ruckman Tom De Koning was only able to be selected as the substitute after a lay-off with a foot injury. 

The Blues' season ended with a 28-point loss at the Gabba on Saturday night after the Lions raced to a 60-point lead during the second quarter and then held off a mini-fightback through the second half. 

De Koning, who had not played since round 19 because of a foot injury, was one of six Blues selected to return from injury for the crucial match and was influential after being injected as the substitute 11 minutes into the second quarter. 

Voss said he was glad he pulled the trigger early to get the dynamic big man into the game, but he was unable to select him for a full match given the 25-year-old's interrupted preparation. 

"I'd love his availability, there's no question on that. I think if we'd had our way, we'd love to start them all at the same time," he said. 

"(But) Tom was probably just one or two runs short of being able to put in 100 minutes, for example. 

"So the option was to either not play him or play him in that scenario. We chose to want to activate him, and I'm pleased we did as it turns out because we needed a little bit of presence down the line and clearly forward of the ball we couldn't win many contests. 

"Being able to have Tommy and 'Pitto' (Marc Pittonet) go in tandem for the most part of the game at least gave us a chance."

LIONS v BLUES Full match coverage and stats

The Blues selected Harry McKay (quad), Mitch McGovern (hamstring) and Zac Williams (hamstring) after short absences and backed their body of work across the season to get them through. 

De Koning, Adam Cerra (hamstring) and Sam Doherty, who had not played since suffering an ACL injury in Opening Round, presented more unique circumstances for the coach.

"If you look at the individuals themselves, they've all got through the game OK," Voss said.  

"We tend to put them all in the same basket, but the reality is they are all different. 

"We had three guys that had missed one or two weeks, so they've played a body of work over the course of the season and that doesn't really impact them.

"And obviously we had the other ones, which are namely Doc and Cez and Tom."

Asked about the team's inability to nullify Brisbane star Dayne Zorko, who was influential off half-back with 19 first-half disposals, Voss said there was a plan in place from the start of the game, but it was not executed well enough.   

"The reality is that probably tonight was a really small sample size of what our season's been. It hasn't been consistent enough, and when you're not consistent enough it compounds over time," he said. 

"You come to finals and it's put up against the best sides in the competition under the most extreme pressure in an away venue, and you find out a bit about yourselves.

"We just weren't able to play with any real consistent execution across the night and we didn't have our pressure at anywhere near the levels that it needed to be.

"If you don't build those habits for long enough over the course of the season, you find out when you come to these sorts of games. So that's our challenge moving forward as a footy club."

The Blues remain an unfinished product, Voss said, 12 months after losing a preliminary final against the Lions by 16 points at the Gabba.  

While they won the second half on Saturday night by 20 points, they were still short of having the "consistent winning behaviours" needed to make the leap into the next bracket. 

"Going from 13th to eighth, that's not the hard part. Going from eighth to fourth, top four, going first, that's the hard part," he said.

"The results say we're not as far advanced as we'd like to be. That's what the result says, so we won't shy away from that. We want to be better than what we did tonight.

"So the demand comes with being able to try and make sure that we get better and that we do it over a consistent period of the season.

"There's personnel that goes into that, there's a method that goes into that, and we've clearly got to get after a fair bit more because tonight wasn't good enough.

"I think we can emphatically say we don't like where we are, and we've got to get better."