Adelaide Crows forward Riley Knight is in doubt for the start of the 2018 AFL season after going under the knife to correct an ankle issue.
The rising star underwent minor surgery on the fat pad in his heel on Tuesday which was cauing irritation, ruling him out for up to six weeks as he recovers.
The 22-year-old will miss the rest of the pre-season Crows high performance general manager Matt Hass confirmed in a statement.
"Unfortunately, Riley started to feel some soreness in his ankle and it was decided that surgery was the best course of action," Mr Hass said.
"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."
Knight enjoyed the best season of his young career last year where he played 19 games, including the 2017 Grand Final.
He was on course for another strong season after turning heads on the training track.
The young speedster claimed back-to-back first place finishes in the 2 kilometre time trail for first-to-fourth-year players in November.
Knight then placed third in the time trial when players returned after the Christmas break, finishing behind veteran Sam Gibson and fellow young gun Jake Kelly.
It is another cruel blow for the former South Clare junior who has struggled with injuries since he was drafted in 2013.
In both 2015 and 2016, Knight battled ankle injuries which limited his opportunities to don the tri-colours for the senior side.