A PASSIONATE Brendon Bolton refuses to put a timeframe on when Carlton's reset will be complete but is hell-bent on his club not falling "off the cliff" again.

The Blues' 0-3 start has heightened scrutiny on the path they are on under the third-year coach, but Bolton, appearing stung into action by recent media criticism, spoke more openly on the eve of Carlton's Round 4 clash with North Melbourne in Hobart about the direction his side was going.

"You can only look at history and look at other clubs, so that's for you guys to go and do the hunting on," he said in response to a question about how far the Blues were from the finals.

"But what I do know is there has been a club that's stripped it right back and we've gone to the draft.

"How long that takes – I know a lot of people want me to say it's one year, it's two years, it's three years, and then all there is, is a big story that we haven't got there or we have got there quicker.

"We're just concentrating on sticking to that plan, growing as a club and, in time, we'll look at the free agency market when … it's the right time for us and we'll look at uncontracted players."

Bolton and list manager Stephen Silvagni, a club legend, have turned over a whopping 42 players in the search for success since joining forces at the end of the 2015 season.

The coach placed a strong emphasis on defence last season – a focus that kept Carlton competitive for much of the year – but has loosened the reins in 2018 to promote more offence.

The Blues have not scored a triple-digit tally in the past 36 games, a period in which they have lost 29 times.

"I think the main thing the Bluebaggers want is absolute clarity and understanding about where we're at," Bolton said.

"I know they wanted two years and a few games ago to go to the draft and build, so we've done that. There's a lot of turnover of the list and now they need to grow together.

"The story doesn't change, we're not going to deviate – we can't. There's just a reality there are some guys who haven't played together for a long time and in age and experience, that's not there yet.

"But our supporters must know we're holding them to account in (areas like) how to defend, moving the ball better – it's not like that's not happening, and I think they appreciate that."

Bolton said the players and his coaching staff were not "down in the dumps" about their on-field results, and the mood at Ikon Park was "more of determination" rather than being "sombre".

"I think last week the blue skies of it was we are getting the ball inside 50," he said.

"We've grown by about plus-10 – 55 or 56 inside 50s we're averaging – so there's some growth there, and we're not giving up a considerable amount of inside 50s against in the last two weeks.

"However, when they do get through, they're scoring, so just some detail in and around our defensive mechanism (needs improvement)."

Bolton hinted that ex-Port Adelaide recruit Cam O'Shea would take over the injured Caleb Marchbank's defensive role for the match-up with star Roos Ben Brown and Jarrad Waite.

Sam Kerridge and Nick Graham are also in contention for a senior recall after strong VFL form.

But Bolton restated that key forward Harry McKay, who has battled repeated injuries since being the No.10 draft pick in 2015, was not ready for a call-up.