CARLTON coach Brendon Bolton remains 'rock solid' with his plans for the rebuild at Carlton despite a dirty night in Hobart on Saturday.

Bolton said a focus on improving defensive structures will be the focus before taking on the in-form Eagles next weekend.

Thrashed by 86 points by a rampant Kangaroos outfit, Bolton refused to look for a silver lining and admitted his side has lots of work to do to turn its season around after lurching to an 0-4 start in Hobart.

"Our group, our leaders and our younger guys said they needed to spread the load and have more contributors, so that's the summary," he said.

"We are rock solid in our plan, I spoke about that during the week. We've just got to gel together (and) get our defensive action on track."

The Blues lost Marc Murphy minutes before the opening bounce but it would have taken more than a typically solid contribution from the captain to reverse the result.

They were smashed for contested ball by the hungry Kangaroos and struggled to live up to Bolton's expectations in terms of their 'defensive action' as Ben Brown kicked five majors to outscore the Blues off his own boot.

"We'll go and analyse the tape thoroughly. We'll challenge scores against, look at all that… but we are in it together as a group, coaches and players and that's what makes strong footy clubs.

"You can't do this on your own. It's about all of us staying fat."

The Blues won't know how long they'll be without Murphy until scans during the week, and may also be sweating on the fitness of widely scrutinised key defender Jacob Weitering who played sore after picking up a cork in his leg and spending significant time on the bench after half-time.

"Right now I'd rather not talk about any blue skies of the game," Bolton said. "We're disappointed because we've got a fair bit of work to do.

"Frustrated, disappointed and not what we stand for.

"In saying that, they are determined. They are determined to grow as a group.

"We've got to roll our sleeves up."