MIDFIELDER George Hewett has been ruled out of Carlton's crunch game against Essendon on Sunday night, while a key pair must pass fitness tests to be available.

Coach Michael Voss said on Thursday Hewett would sit out a second match after suffering a concussion during the Blues' loss to Sydney in round 11.

Voss also noted that ruckman Marc Pittonet is unlikely to feature at the MCG, but will be tested to see if he is fit as he recovers from a hand injury.  

"He's got to get through a couple of things today," he said. 

"At the moment, I guess we're planning without him, but we'll see whether anything shows up today that says that he's ready to go."

Jack Silvagni also faces a fitness test before he is confirmed to line up against the Bombers, after he was subbed out against Melbourne at half-time with a hip complaint.

"He'll have a couple of things that he needs to be able to get through before he becomes available," Voss said. 

Voss also said draftee Jaxon Binns continues to put himself into contention for a senior debut, after a run of impressive form in the VFL.

Sitting 14th on the ladder amid a five-game losing streak, Voss admitted that he has made it a focus to "stay in the present" after much external scrutiny.  

"We have to spend the energy in the right areas," he said.

"I just know that at the other end of this is going to be a really strong, united group."

The Blues now turn their attention to another edition of their long rivalry with Essendon. 

"When you're playing against Essendon it always has a little bit (of an) extra edge to it," he said.

"It's a great opportunity for us to be able to go out and put out the best version we possibly can against ourselves, against a really great rival that we've had over such a long period of time."