CARLTON'S players are exhausted from six weeks of trying to "keep their heads above water" against sides with serious finals aspirations, coach Mick Malthouse says.

The Blues were put to the sword by a determined Port Adelaide outfit on Friday night, suffering a 103-point loss - their worst since late 2007.

The performance came just a week after Carlton went so close to upsetting premiership fancies Geelong last Friday night.

But the aftermath of the gutsy effort told Malthouse his playing group was cooked, having played various teams with more on the line than his.

 

"I learnt during the week that they were desperately tired, trying to keep their head above water against sides that are all in, or fighting for, a position in the eight," Malthouse said.

"There's no excuse for 100 points, let me start by saying that, but having been there before, it's so desperately tough to get up every week, fighting against a side that is either in the eight or fighting for a position in the eight.

"And Port are coming into a finals series, they ... will worry the life out of a lot of sides."

The Blues had 11 players unavailable for selection on Friday through injury, an issue made worse when skipper Marc Murphy was concussed in a heavy knock in the second term.

Murphy was taken to hospital for scans in Adelaide as a precaution, which cleared him of any structural damage.

Malthouse supported the introduction of a six-man interchange bench to help ease the burden on fatigued players.

"I argued this case in 1985 in my second year (as coach) and they all looked at me like I was a man from wherever," he said.

"I don't suspect for one moment it will ever get near that (six interchange players).

"But I think the way the game has gone, the power athlete today is greater than what he was yesteryear.

"The intensity of the game - we can make out whatever we like about us old players - the game is comprehensively better and comprehensively quicker and stronger."

The reaction from Carlton's players as the third-term siren sounded spoke volumes for their collective mental state.

Port's lead was 86 points and the siren robbed Power star Robbie Gray of a possible shot on goal; he threw his head back in disappointment.

Most of the Blues' heads were slumped forward in defeat.

"That is the most miserable we have played probably since the Essendon game," Malthouse said, referring to the club's 81-point round-three loss.

"We don't make excuses but our blokes have been up for so long, we're on our knees with injuries.

"I think it would be unfair if we said 'that is us'."