Magpies lose O'Brien for Blues' AFL clash Collingwood have suffered a blow on the eve of their AFL round-15 match against arch rivals Carlton, with defender Harry O'Brien ruled out because of ankle injury. Eighth-placed Collingwood have left out O'Brien and big forward Quinten Lynch (back) because of injuries while Jordan Russell and Kyle Martin have been dropped ahead of Friday night's MCG blockbuster. Small forward Andrew Krakouer and defender Ben Reid return alongside ruck/forward Jarrod Witts and Hawthorn's 2008 premiership player Clinton Young who makes his debut for the Magpies. Carlton, who sit two wins behind the Magpies in ninth spot, are in danger of slipping out of finals contention if they can't overcome Nathan Buckley's Magpies. The Mick Malthouse-coached Blues have been boosted by the return of skipper Marc Murphy from a cheekbone injury and fellow midfielder Andrew Carrazzo plus defender Andrew McInnes. Injured defender Heath Scotland is out for the Blues against his old side along with Simon White and Josh Bootsma (injured). Matthew Pavlich and Aaron Sandilands are among key inclusions for fifth-placed Fremantle who host St Kilda in Perth on Sunday. Ruck/forward Sandilands tore a hamstring in February, while Pavlich hasn't played since round three because of surgery on his plantaris tendon. Six-time All-Australian Pavlich says it has been a tough fight to regain full fitness. "The both of us had some dark days throughout the rehab process," Pavlich told FoxFooty's AFL360 program. The 15th-placed Saints go into battle without skipper Nick Riewoldt who has been listed on the team sheet as having soreness, as does fellow key forward Justin Koschitzke. Brisbane's Brownlow Medallist Simon Black is out of Saturday's Gabba clash with Queensland rivals Gold Coast with a groin injury while Karmichael Hunt (calf) will miss the game for the Suns. Cyril Rioli, back from a hamstring injury, is one of three inclusions for Hawthorn who face Geelong at the MCG on Saturday night in a top-of-the-table encounter. Paul Puopolo and ruckman Max Bailey also return in place of Liam Shiels (ankle), Xavier Ellis (calf) and Jonathon Ceglar (hip). Adelaide have recalled Shaun McKernan for Saturday night's home game against West Coast who will be without rover Daniel Kerr (ribs), Ashley Smith (calf), Sam Butler (back) and Scott Tunbridge (omitted). Key forward Jeremy Cameron returns from injury for Greater Western Sydney who will chase their first win of the season in Saturday's clash with 16th-placed Western Bulldogs in Canberra. North Melbourne (12th) have recalled Ben Cunnington for suspended forward Lindsay Thomas for Saturday's game at Etihad Stadium against the surging sixth-placed Richmond, who've recalled Nick Vlastuin. Melbourne have named co-captain Jack Grimes for Sunday's game at the MCG against Sydney who regain ruckman Shane Mumford and key forward Sam Reid. Veteran Dustin Fletcher returns for Essendon who host Port Adelaide at Etihad Stadium on Sunday. Stewart Crameri is out of the Essendon side with an ankle injury while Port will be without Dom Cassisi because of a hamstring complaint.