ADELAIDE has been dealt another blow in the lead-up to the start of the home and away season, with forward Chris Knights expected to miss up to six weeks with a foot injury.

Knights raised eyebrows last week when he appeared at the Crows' training camp on the Gold Coast with a moon boot on his left foot.

Club officials said the 23-year-old was suffering from plantar fasciitis, but a subsequent MRI scan showed he also had a stress fracture.

"Late last week Chris was aware of pain and swelling further down the foot towards the toes. An investigation (MRI scan) on the weekend revealed a stress fracture," club doctor Andrew Potter told afc.com.au.

"Chris will continue to have treatment for both plantar fasciitis and the stress fracture."

Knights joins high-flying forward Brett Burton and midfielder Nathan van Berlo on the list of players in doubt for Adelaide's round one clash with Fremantle on March 28.

Burton, 31, had surgery on his troublesome left knee last week, while van Berlo is still battling a stress fracture in his back.

Andy Otten will miss the entire season with a torn anterior cruciate ligament, while Brodie Martin is aiming for a round 17 return from the same injury.

In better news for the Crows, key trio Nathan Bock, Scott Thompson and Kurt Tippett are all likely to be available for Friday night's NAB Challenge game against Collingwood, after being rested in the first week of the pre-season competition.

Brad Symes (knee), Jason Porplyzia (pelvis) and Brad Moran (knee) are also on track to play before the end of the pre-season.

Chris Knights is a $372,000 forward in this year's Toyota AFL Dream Team.

Kurt Tippett is a $319,400 forward/ruckman.

Nathan Bock is a $386,400 defender.