CURSED Cat Josh Cowan's horror run of injury looks set to continue with leading sports medico Dr Peter Larkins expecting the 24-year-old to miss 5-6 weeks with the right hamstring injury he suffered against Collingwood.

Cowan was playing his first game since round 18, 2011, last Friday night after recovering from a series of Achilles tendon and hamstring injuries, but lasted just 23 minutes before being substituted out of the match.

Larkins told AFL.com.au that Cowan had suffered a "high-level" hamstring injury against the Magpies.

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"Unfortunately, Josh Cowan has suffered a significant setback in his first game back for Geelong," Larkins said. 

"Geelong will go back to square one with rehabilitation because he's been out of footy for so long.

"He'll have to come back via the VFL and it wouldn't surprise me if it's an injury that costs him 5-6 weeks before he's back to playing senior football again." 

The Sydney Swans have said they expect star youngster Isaac Heeney to miss 4-6 weeks with a right posterior cruciate ligament injury he suffered against Melbourne last Saturday night. 

But Larkins said Heeney could be sidelined for up to eight weeks. 

"I know the Swans have said he'll be out for 4-6 weeks, but that's at the lower end for most people with a PCL," Larkins said. 

"Isaac collided with a player in mid-air and that's the old ruckman's injury that we've managed to eliminate mostly from the AFL.

"It's normally not an injury that needs surgery, but the swelling and soreness in the knee and the need to use a brace in rehabilitation mean that most players miss 6-8 weeks on average, more often than not it's closer to eight.

"Hopefully his injury will be at the lower end because we weren't expecting it to be a higher-grade injury."

Adelaide announced on Monday afternoon that midfielder Rory Sloane would be sidelined for 4-6 weeks after suffering a fractured cheekbone that would require surgery.

Larkins said plates and screws would most likely be required to stabilise a displaced fracture in Sloane's left cheekbone.

"Six weeks is generally the standard recovery time for these type of injuries in AFL circles, but occasionally players do return sooner," Larkins said. 

Last round was a bad one for serious knee injuries, with Western Bulldog Clay Smith rupturing his right anterior cruciate ligament for the third time in two years and Giant Tim Mohr rupturing his left ACL for the second time in less than 10 months.

Smith went back on to the ground after rupturing his ACL against St Kilda on Saturday but was forced off the ground about 15 minutes later when his knee gave way again.

Smith decided to play on after his original injury because he was not in a lot of pain and was able to run and jump.

Larkins said the Bulldogs' medical staff was "100 per cent" confident Smith had completely ruptured his ACL graft and had taken a "calculated risk" he wouldn't suffer further damage to his knee. 

"There has to be some doubt now as to whether he'll get back to senior level but I know he'll go through the process and the club will support him and give him every chance," he said.

Mohr was playing his sixth game back in the NEAFL when he suffered his injury, with Larkins expecting the Giants defender to be sidelined for 12 months.

Larkins also said:

- Joel Selwood had originally injured his right hand in round five against Richmond and aggravated it last Friday night against Collingwood. The Geelong skipper has been cleared of any fractures and despite ongoing bleeding and soft-tissue swelling should play against the Sydney Swans this Saturday.

- Fellow Cat Harry Taylor was struggling with a corked left thigh late in the win over Collingwood but Geelong expects that with treatment he'll be able to play against the Swans.

- Dan Hannebery has a history of ankle injuries but with strapping and physiotherapy should overcome an injured left ankle to take on the Cats.

- Brad Ebert suffered a "very significant" corked thigh against West Coast on Sunday but with treatment this week should be fit to play for Port Adelaide against the Brisbane Lions on Sunday.

- Port is also optimistic spearhead Jay Schulz will play against the Lions despite suffering a heavy cork to his right glute against the Eagles.

- Magpie Sam Dwyer was subbed out at half-time in Collingwood's loss to Geelong on Friday night with a "painful" right ankle and lower shin injury. Collingwood is confident Dwyer will be able to train later in the week, but he remains in doubt for Sunday's clash against Richmond.

- Western Bulldog Koby Stevens copped a heavy knock to the lower part of his back or hip pointer against the Saints and was quite sore after the game. But the midfielder will have a lot of physiotherapy this week and remains a reasonable chance to play against Fremantle on Sunday.

- Saint Shane Savage and Tiger Ben Griffiths will have to pass the standard concussion protocols to play this round.