MARC Murphy is edging closer to playing in Friday night's crunch clash against North Melbourne, but a decision on whether the star onballer will play will be left until the last possible moment.

Murphy suffered fractures in his left shoulder in a high-speed collision with Adelaide's Patrick Dangerfield in round eight, but is being tested in full training at Visy Park this week as he steps up his bid to return after missing just six games and a bye.

"He was out on the track, but we'll just have to see how he pulls up and what the risk is to play him," coach Brett Ratten said on Tuesday.

"We think he's heading in the right direction, but we'll make a call after today and then we'll see how he goes Thursday.

"He's not a lock-in ... as we know with football, things can change fairly quickly so let's see how he pulls up.

"He's having more physical tests on him, so he's going well."

The news is not as positive for important talls Lachie Henderson and Jarrad Waite as they look to resume from their respective groin and back injuries.

"I think Waite's still a week or so away and Henderson's getting closer, but it's a bit the same," Ratten said.

"Most of these boys have just got back into the program whether it's straight line skills or game simulation work that we do, it just depends how they pull up.

"It will be a session-by-session assessment of those players."

Ratten would dearly love to have both of those players at his disposal after losing Kade Simpson (jaw) and Shaun Hampson (knee) for extended periods following Friday night's confidence-boosting win against Collingwood.

The coach wouldn't be drawn on the three-game penalty handed down to Collingwood's Sharrod Wellingham, but he did reveal Simpson's recovery period could be longer than the four weeks initially diagnosed.

"He might miss six weeks ... he can't get an operation, so he has to get a band with braces to lock that jaw in," he said.

"He could be up to six weeks [out]. It's four to six."

Questions were raised in some quarters over the way Simpson was walked off the ground by the Blues' medical staff after the sickening hit, but Ratten said: "[We will] back our medicos in every day of the week".

Carlton's clash against the Kangaroos takes on added significance given both clubs are part of a group of five teams locked together on seven wins and seven losses that are vying for a top eight spot.

"We've put ourselves in that position and that will be the challenge in trying to get that ledger back above [even]," Ratten said.

"We're under where we want to be with the wins above the losses ... we've had that around the wrong way for about three weeks now, so it would be good to jump back in the positive."