HAWTHORN is almost certain to be without Cyril Rioli for Saturday night's clash with Collingwood and is sweating on the fitness of Ben Stratton after the pair was unable to finish the game against the Brisbane Lions.

Rioli was forced off the ground just before three-quarter time after his left knee collided into Lion Josh Walker's back in a desperate spoiling attempt.

The 27-year-old was assessed at the last break and spent the final term with ice on his affected knee.

Hawthorn coach Alastair Clarkson described Rioli's injury as a "PCL mechanism", with the full extent to be known following scans.

Hawks defender Stratton, meanwhile, first had his right knee assessed at the start of the second term and was limping noticeably early in the third quarter.

The 28-year-old finished the afternoon with ice on his knee from midway through the third term.

Statton's setback comes just a week after fellow premiership backman Grant Birchall was sidelined for up to a month with a right posterior cruciate ligament injury. 

Greater Western Sydney ended the thrilling game against Collingwood with just one fit player on the bench after vice-captain Stephen Coniglio limped off with a left ankle injury in the closing minutes – the same ankle he injured in the pre-season.

The 23-year-old midfielder appeared to kick Magpies forward Darcy Moore's leg at a contest inside the centre square.

Coniglio missed the first six rounds of the season because of a left ankle syndesmosis injury he suffered in the final JLT Community Series hit-out against North Melbourne in March.

The Giants were left with two players short on the bench for most of the match due to separate concussions to defender Aidan Corr and forward Sam Reid in the first half.

Corr was knocked out in the opening minute of the game after taking a courageous mark running back with the flight of the ball, before being accidentally tripped by teammate Phil Davis as he stepped back.

The 22-year-old went off in the hands of trainers and watched the rest of the match from the bench.

Reid was also left dazed and unable to return when Magpies midfielder Levi Greenwood ran into him in a second-quarter tackling attempt, which forced his head to hit the ground.

St Kilda defender Jimmy Webster is likely to be sidelined until after the Saints' round 11 bye to nurse the broken right hand he suffered after being stood on by Carlton ruckman Matthew Kreuzer midway through the first quarter.

Webster went to the rooms for assessment and did not reappear for the rest of the opening term.

The 23-year-old looked set to take his place in the second quarter, but he went back down the race for further treatment and remerged donning a tracksuit top and with his injured hand heavily strapped.

Brisbane Lions vice-captain Tom Rockliff suffered a painful dislocated shoulder in the closing minutes against Hawthorn.

The 27-year-old sustained the injury in a seemingly innocuous incident while locked in a contest at ground level with Hawthorn midfielder Liam Shiels.

The medicos popped Rockliff's already strapped left shoulder back into place and will assess him further this week.

Melbourne defender Jayden Hunt was knocked out instantly after colliding into Adelaide ruckman Sam Jacobs' shoulder at full speed early in the third quarter.

Play was halted for several minutes as the 22-year-old was taken off on a mobile stretcher.

Hunt, who gave the thumbs up to the crowd as he left the field, was alert in the rooms and watched the rest of the game from the bench.

In other injury concerns in round eight:

- Sydney veteran Jarrad McVeigh experienced hamstring tightness in the first half against North Melbourne, but managed to play on. The 32-year-old will be assessed over the coming days.

- North Melbourne draftee Jy Simpkin injured the AC joint in his right shoulder after coming into contact with Sydney's Lewis Melican in the first term. The 19-year-old returned with a heavily strapped shoulder, but went off soon after being crunched in a second-quarter marking contest. Simpkin left the ground post-match with his right arm in a sling.

- Port Adelaide draftee Sam Powell-Pepper landed heavily on his lower back in a one-on-one defensive marking contest in the second term against Gold Coast, but finished the game.

- Port Adelaide forward Charlie Dixon was assessed for a right knee issue in the third quarter and ended the match with strapping on his leg.

- Gold Coast defender Rory Thompson injured his hamstring during the warm-up of his side's clash against Port Adelaide and was withdrawn.

- Geelong ruckman Rhys Stanley hurt his right knee as he landed in a marking contest late in the game against Essendon. Although Stanley left the field with the help of trainers, Cats coach Chris Scott said he was "really confident he'll be available" to face the Western Bulldogs on Friday night.

- Adelaide forward Troy Menzel did not feature in the final quarter against Melbourne because of groin soreness. Crows coach Don Pyke said early indications suggested Menzel's complaint was nothing serious.

- St Kilda defender Jake Carlisle received an accidental Levi Casboult knee to his groin in a marking contest late in the third quarter against Carlton. Carlisle looked in pain as he jogged off the ground, but returned in the early part of the final term.

- Saints midfielder Luke Dunstan picked up a left knee complaint in the third quarter after being tackled by Charlie Curnow on the wing. The 22-year-old managed to shrug off the knee niggle following a spell on the bench.

- St Kilda defender Dylan Roberton received a knock to his right elbow in a final-quarter contest with Blues defender Sam Rowe. The 25-year-old had his elbow strapped and appeared to avoid any serious injury.

- Fremantle defender Cam Sutcliffe needed treatment for a cut head he received from an accidental boot to the face from Richmond midfielder Shaun Grigg in the second quarter.

- West Coast defender Jeremy McGovern received a knock to his right knee on the wing early in the third quarter against the Western Bulldogs, but came back and got through.