CARLTON will be without promising ruckman Tom De Koning throughout the early stages of the club's upcoming campaign, with the youngster suffering a low-level stress reaction to his back since returning to pre-season training.

Earmarked as the natural successor to the recently retired Matthew Kreuzer in Carlton's ruck division, the 21-year-old enjoyed a breakout campaign last season and featured in seven of the club's final eight games.

However, having been expected to compete with Marc Pittonet for the No.1 ruck spot ahead of the club's season-opener against Richmond on March 18, De Koning will now be sidelined for the foreseeable future.

"Given the nature of this type of injury, we suspect Tom will miss the first few games of the season to allow his body to rest and recover accordingly," Blues football boss Brad Lloyd said on Thursday.

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"We expect at that point that Tom will then be available for selection."

De Koning signed a two-year contract extension with Carlton in October last year, tying him to the Blues until at least the end of the 2023 season.

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His injury leaves the club short on ruck options ahead of a pivotal campaign for coach David Teague's side, with Pittonet the only other natural ruckman on the list.

Experienced 199cm forward Levi Casboult has also deputised in the position.