Adelaide forward Riley Knight will likely miss round one of the home-and-away season, as he recovers from recent ankle surgery.
Knight had surgery on Tuesday, to rid himself of pain in his heel.
The 22-year-old played 19 games for the Crows in 2017 in his third season at the club, and played in all three of Adelaide's finals matches.
Adelaide's High Performance General Manager Matt Hass told the club's website Knight will likely be unavailable for the next six weeks.
“Unfortunately Riley started to feel some soreness in his ankle and it was decided that surgery was the best course of action," Hass told afc.com.au.
“He will be off legs while he recovers post-operation and we will look to build him back up to full fitness in around six weeks.
“He will not play any part in pre-season matches and we hope he will be available for selection in the early part of the AFL season.”