Midfielder Jake Soligo is out of Adelaide's AFL pre-season match against Fremantle because of an irregular heartbeat.
The Crows revealed on Wednesday that Soligo had been on managed training for the last few weeks because of the condition.
He will not play in Saturday night's game at Mandurah, south of Perth, but the Crows expect him back at training next week.
"The club has liaised with its own experienced medical staff, as well as external specialists, to best manage the 23-year-old’s recovery," the Crows added.
Also on Wednesday, Collingwood coach Craig McRae said captain Darcy Moore and fellow key position player Jeremy Howe are likely to be sidelined for their Opening Round game against St Kilda.
The two veterans have calf muscle injuries.
“They're both unlikely to play early in 'round zero', but they’re maybe touch and go for a little bit after that," McRae told SEN.
“But they’re both progressing well, they’ve just had recurring calf injuries, which is just part of our learning around their bodies.
“But they won't play early in the season.”
It also remains unclear when Norm Smith Medallist Bobby Hill will be back at Collingwood as he continues to deal with personal issues.
"Bobby is working on himself at the moment. We're hoping that he'll be in the program in the short or medium term. We'll see how that progresses," McRae said.
"It's probably a bit too early to say (when Hill will be back), but we're confident that it's progressing."
Hawthorn key defender Tom Barrass will miss Friday night's game against the Western Bulldogs with a sore back, ahead of their Opening Round game the following weekend against GWS.
The AFL website also reported Jack Ginnivan will return from a finger injury against the Bulldogs.
