Murphy could be out of AFL until round 20

After suffering a third loss in the past five AFL rounds, Carlton must deal with having injured star Marc Murphy out of action for up to 12 weeks.

Carlton AFL midfield star Marc Murphy will be out of action for up to 12 weeks after undergoing surgery on his fractured shoulder.

The 2011 All-Australian will have his left arm in a sling for four weeks and might not return to senior football until round 20 in mid-August.

It's a massive blow to Carlton's top-four hopes, after the Blues dropped three places to seventh on Sunday following their 69-point loss to Adelaide, their third defeat in the past five rounds.

"It's probably somewhere between eight and 11 or 12 weeks, we're not exactly sure," Carlton football manager Andrew McKay said on Tuesday.

"It just depends on how the bone fuses up initially.

"Murph's a really good player. He won the best and fairest last year and is a prime mover in our midfield.

"We haven't been going so well in the clearances of late so we'll miss him dearly."

Murphy was injured in a massive collision with Adelaide's Patrick Dangerfield during the second quarter of Sunday's match at Etihad Stadium.

McKay said key forward Jarrad Waite, who missed the Adelaide game with a stiff back, was still sore.

"We're just going to hang out until later this week to see if it's improved enough to get him out on the field," McKay told SEN radio.

The Blues host winless Melbourne at the MCG on Sunday in round nine.