While the Cats have recalled big guns Cameron Mooney and Matthew Scarlett, Chapman’s omission came as a surprise after he had not appeared on any of the club’s injury lists, suggesting he may have sustained a fresh strain at training in recent days.
The star midfielder has been in scintillating form this season and was the difference between the two teams when they met last September, playing through a hamstring injury for much of the grand final to finish best afield.
Simon Hogan is the other Cat to go out of the side.
Chapman is one of several big names to be missing this week.
Josh Fraser will have to wait another day to play his 200th AFL match, with Collingwood making five changes to its team for Saturday night’s clash with the Sydney Swans at ANZ Stadium.
While the Pies have regained Alan Didak, Luke Ball and Ben Johnson from injury, they have also recalled Chris Dawes and Tyson Goldsack, the latter for his first game of 2010.
However, skipper Nick Maxwell (calf) won’t make the trip to Sydney.
Four players have been dumped from the Magpies’ side, with Fraser and out-of-form forward Paul Medhurst the big-name omissions. Brent Macaffer and Jaxson Barham also make way for the influx of new players.
But Fraser’s uncertain future is the talking point, with coach Mick Malthouse opting to go with one specialist ruckman - former Swan Darren Jolly - against Paul Roos’ side.
Jolly will carry the load, with the likely assistance of Leigh Brown and Dawes, against in-form Swans pair Shane Mumford and Mike Pyke.
Fraser is an emergency and is likely to make the trip to Sydney.
The Sydney Swans have made two changes to the team that easily accounted for Port Adelaide in its last outing, both significant.
Leading goalkicker Daniel Bradshaw returns to the side after missing three matches with a knee injury, while running defender Rhyce Shaw also returns. Youngsters Patrick Veszpremi and Gary Rohan miss out.
St Kilda has made just one change for its clash with the Cats, promoting youngster Jack Steven in place of the injured Raphael Clarke (hamstring).
Sean Dempster and Zac Dawson are among the emergencies.
Adelaide has lost creative defender Nathan Bock to a groin injury but has added four players to its extended squad for Sunday’s home clash with Melbourne.
Matthew Jaensch and Phil Davis have both been named in the starting side, while Bernie Vince and James Sellar will also press for a spot in the final 22 when coach Neil Craig trims his squad on Friday night.
Despite some promising opening matches, Melbourne will give youngster Jordan Gysberts a breather but may recall up to four of his teammates.
Joel Macdonald, Kyle Cheney, Jake Spencer and Jamie Bennell are all on the extended interchange and will hope to win a spot for Sunday’s clash at AAMI Stadium.
