Cleary reports that the 28-year old has experienced soreness in the same knee he injured last year and has had early signs of inflammation behind his kneecap.
The club confirmed in a statement that Newman was likely to miss the start of the season.
It is a blow for the Blues ahead of what looms as a critical year for the club with genuine finals aspirations.
He will meet with specialists on Monday to determine his plan moving forward and how much training he will miss.
“‘Newy’ was going really well with his knee: he got back into the full ball program and was doing game play,” Blues director of high performance Andrew Russell told carltonfc.com.au.
“His patella tendon looks really good, which is the injury he had last year, but the back of the kneecap is a bit inflamed at the moment. We’re still deciding what that means and how much training he’s going to miss.
“We need a bit more information to find out how long: it will settle down and he will be playing footy, but it probably won’t be at the start of the season.”
The 28-year old was restricted to just two senior games last year after rupturing his patella tendon during Round 2.
Newman moved from the Swans to the Blues at the end of 2018 and enjoyed his best season to date in 2019, averaging 21.4 disposals and 6.8 marks from 20 games.
In other news, the Blues announced that Eddie Betts (calf), Levi Casboult (knee) and Mitch McGovern (hamstring) will all miss Thursday’s practice match against Essendon but are expected to be available for Round 1, while Tom De Koning (back) could be back running in the next week.
However, AFL Media’s Riley Beveridge reports that McGovern is in doubt to feature in the season opener, while Caleb Marchbank (calf) is set to miss the annual Tigers clash.
Luckless Carlton defender Nic Newman has suffered another knee setback. More soon on @AFLcomau
— Mitch Cleary (@cleary_mitch) February 22, 2021