Carlton is carrying a handful of players who are going through the motions and not displaying the necessary grit to succeed at AFL level, interim coach John Barker says.

Barker was speaking after the Blues followed their record 138-point loss to Hawthorn in round 17 with a 64-point loss to North Melbourne at Etihad Stadium on Saturday night.

The Blues' pressure was almost non-existent in the first term and they were lucky to be just 24 points down at the first break after conceding nine marks inside their defensive 50.

They came to life in the second quarter, piling on five goals to the Roos' three, and were still well in the game until late in third term.

But the Blues fell away badly from there, allowing North to kick nine of the last 10 goals.

Barker lauded the performances of Blues skipper Marc Murphy (26 possessions and five clearances), ruckman Matthew Kreuzer, who battled valiantly against star Roos ruckman Todd Goldstein, defender Simon White and midfielder Patrick Cripps (21 and seven).

"We have some players who are digging in, rolling their sleeves up and our captain's leading from the front, but we can't do it with a handful," Barker said.

"There's a handful of players who are now just not displaying that sort of grit.

"One going through the motions is too many, but at the moment I think maybe we have ourselves a handful, which is disappointing.

"It would be nice to turn them over, but we're starting to lose some of our levers at match committee because of 14-15 who are unavailable.

"We're running out of soldiers."

Barker said it was "very important" for Carlton to re-sign Kreuzer, who is set to become a restricted free agent at the end of this season.

"I'm always happy with Matthew Kreuzer, because he doesn't pick and choose – he's unconditional," Barker said.

"Todd Goldstein is a great ruckman and is obviously a bit taller than Matty. He probably has a few physical capabilities that shade him (Kreuzer) a little bit, but Matthew Kreuzer has a massive ticker.

"He's a Carlton man."

One reporter told Barker there had been a radio report that he was "over the line" in the race to become Mick Malthouse's permanent replacement as Carlton coach.

Asked to respond, Barker said it was news to him.

"I'm currently the interim coach and I will drive this group as hard as I can week in, week out until the end of the season," he said.

"That's all I can say."