The Demons suffered a shock 79-point thumping by Port Adelaide at the MCG on Sunday, but won't be able to call on the services of the ex-Magpie until round five at the earliest.
"Chris is unfortunately having some ongoing issues with his hamstring," Melbourne football manager Josh Mahoney told melbournefc.com.au.
"He’s injured it again during training last week, so at this stage, we’d be expecting the hamstring program to be three to four weeks away from playing."
The 2010 Collingwood premiership player has only played in one NAB Cup clash since crossing to the Demons last October.
Fellow key forward Mitch Clark - who played his first AFL match since round 13 last year, due to a serious foot injury - will face a fitness test ahead of Saturday's contest with Essendon.
Clark sent a scare through the Melbourne camp when he landed awkwardly on his ankle against Port.
"We saw the incident with him where he essentially rolled his ankle," Mahoney said.
"He’s recovered well from it, and he still has to get through some training, but he’ll be tested later in the week for Saturday night’s game."
In better news for the Demons, co-captain Jack Trengove played for Casey last weekend while fellow midfielder Rohan Bail is set to return for Casey this weekend after missing the NAB Cup with concussion.
Towering ruckman Max Gawn also returned in the VFL last weekend and got through well, according to Mahoney.
"Max completed all of his rehab and played for Casey on the weekend," he said.
"He played nearly three quarters of the game and he got through the game and pulled up well, which is a good sign."
Key defender Tom McDonald also came through strongly after returning the VFL.
"Tom returned for Casey after hurting his ankle four weeks ago," Mahoney said.
"He’s had no soreness in his ankle, so he’s pulled up well and he’ll be in contention for this week’s game."
