Carlton star Sam Docherty is set to miss up to six weeks of action after suffering a meniscus tear, with the Blues defender requiring surgery after a concern with his knee.
The Blues will head to South Australia in the coming days to face Adelaide and open the AFL's first-ever Gather Round, an encounter that is set to test Michael Voss' side as Carlton looks to continue their undefeated start to the season.
Their prospects against the in-form Crows have taken a hit however, with Docherty tipped to spend the coming weeks on the sidelines due to a fresh injury setback.
The ailment in question was assessed after Docherty suffered knee soreness in the wake of his side's Round 4 win over the Kangaroos.
Scans have shown a tear in Docherty's knee that will sideline the former Blues captain for at least a month.
"It's no doubt disappointing for Sam to be sidelined for the coming weeks, given he picked up this season right where he left off last year, in great form," Carlton Head of Football Brad Lloyd said.
"He's the ultimate professional though, so once he completes surgery, he'll launch into his rehab and do everything required to get back to play, which we expect to be in four to six weeks."
Docherty has continued to play his influential role at half-back for the Blues this year, averaging 26.0 disposals, 7.0 marks and 3.5 intercept possessions per game.
Carlton are expected to welcome the return of gun midfielder Sam Walsh, who missed the opening month of the home and away season due to a back issue that was first sustained late into last season.
Duo Matt Kennedy and Jack Martin may also be in the mix for Round 5 after nursing calf issues over the past week.
The Blues could be without star forward Harry McKay for their clash with the Crows however, with Carlton set to challenge the Match Review Officer's one-game suspension for Striking North Melbourne's Harry Sheezel.
The Tribunal hearing for McKay's case will get underway at 5:00pm (AEST) on Tuesday.
Carlton will face the Crows at Adelaide Oval at 7:10pm local time on Thursday night.
