CARLTON might have been able to successfully overturn Lewis Young's one-game suspension at the AFL Tribunal on Tuesday night, but the club's legal team won't be able to solve the entirety of its key defensive woes.

Young's availability will give the Blues short-term relief, but the cupboard down back is looking increasingly bare. Mitch McGovern and Oscar McDonald's latest setbacks provide more overwhelming evidence of that.

McGovern was on the cusp of returning from a six-week hamstring injury when he reaggravated the issue at training last Thursday. Scans conducted over the weekend have determined that the side's primary interceptor must now undergo further surgery.

MEDICAL ROOM Check out the full injury list

The injury-plagued utility is expected to be sidelined for up to three months and faces a race against the clock to prove his fitness ahead of September, where a first Carlton finals appearance in nearly a decade appears likely to eventuate.

McDonald, meanwhile, is again battling a similar back injury that kept him absent for almost the entirety of last season. It comes after the former Melbourne defender had established himself as a first-choice member of Michael Voss' new-look back seven.

While McDonald has been training intermittently – and even trained on Wednesday morning – the Blues have not yet been able to integrate the 26-year-old back into the full program. The timeline for his return is frustratingly indefinite.

While there have been fears McDonald could miss a large chunk of another season, Carlton is still determining his availability on a week-by-week basis. As for whether that moment arrives next week, next month, or next year, though, there is no way of knowing.

IN THE MIX Who's pushing for selection in round eight?

The absence of both McGovern and McDonald has forced Carlton – already without Liam Jones to a sudden and unexpected retirement late last year – to rely heavily on Jacob Weitering and Young.

Luke Parks, a rookie, has been called upon already to provide another bigger body in the backline, but even he will be forced to miss at least the next month, having battled a foot injury recently.

Caleb Marchbank, meanwhile, is still recovering from an ACL injury sustained last April. He has re-joined the full training program, but is now undergoing a strict block of conditioning work to ensure he is 100 percent fit to return.

His senior comeback is expected to be slow and gradual and will include several weeks of VFL football beforehand. The club will take a cautious approach, given he hasn't featured at AFL level since June 2019 due to neck, knee, calf and now further knee issues.

The lack of key defensive depth in reserve has forced Carlton officials to swing further changes to youngster Brodie Kemp's schedule. The former first-round pick spent almost all of last summer, and the first six weeks of this season, trying his hand forward.

However, standing at 193cm, Kemp was asked to return to a defensive role for last week's VFL clash with North Melbourne. The Blues were forward-planning in preparation for a worst-case scenario – like Young getting suspended – potentially occurring at AFL level.

Kemp is expected to continue in his defensive role at reserves level for the foreseeable future, with Carlton wary he is now one of – if not the only – last remaining key-position options to call upon within its depth.

Lachie Plowman, at 192cm, and Nic Newman, at 187cm, have played above their height in the past. They look set to retain their spots in the back seven, at least in the short-term, and may be asked to play taller sooner than they had once probably imagined.

Expect that to come this weekend, when the Crows – with key-position trio Taylor Walker, Elliot Himmelberg and Lachie Gollant, as well as Riley Thilthorpe and Darcy Fogarty in reserve – stroll into town on Sunday evening.