Carlton's chances of returning to the top eight have fallen further out of their hands following their loss to Collingwood on Sunday, with Port Adelaide record-games holder Kane Cornes questioning the club's stunted youth.

Sunday's clash was a must-win for David Teague's finals birth, with the Blues now sitting in 12th position and four points behind the the top eight.

The Blues haven't featured in a finals campaign in seven years, with Cornes ridiculing the development of their top draft selections across that period.

“I walk away from the game thinking it’s the same old Carlton and any of the good work that’s been done this year has been erased,” Cornes said on SEN's Whateley.

“Who has improved as a Carlton player this year? Sam Petrevski-Seton is a classic example, top 10 draft pick, has played some OK footy and started in the midfield before moving to half back. They basically drop him – or manage him – you don’t manage a player for what is a virtual elimination final (against Collingwood on Sunday) so there’s one.

“Paddy Dow has been mentioned, has he improved year-on-year and are you seeing signs of improvement? I don’t think so.

“Harry McKay, how long has he been in the system and is he improving despite showing glimpses. When will he be a consistent performer at this level?

“Who is improving out of the young group that has had so many free kicks and so many elite draft picks so which one of the players are improving and developing?

Cornes added that the ongoing strains of COVID-19 might be having a large effect on the Blues' growth in 2020, with development coach Jason Davenport being let go due to financial restraints.

“What has been the fall-out of COVID and letting go of your assistant coaches because they’re been so invested in the development space,” he said.

“Jason Davenport and Luke Power have come in so it’s clearly an area they’ve identified so I’m just looking at which Carlton player has improved this year.

“Sam Walsh has improved, there’s no doubt about that and (Jacob) Weitering has been in the system for a long time and he’s had a better year this year than last but which is the young players at Carlton are improving and what is going on with their development.

“We’re six years into a re-build or we’re 20 years into a rebuild but we’re not seeing the improvement that we should be seeing.”

The Blues will face Greater Western Sydney on Thursday, with Sydney, Adelaide and Brisbane rounding out their run home.