ADELAIDE forward Riley Knight is in doubt for the start of the season after having minor ankle surgery.

The recovery time for the surgery is about six weeks, making Knight highly unlikely for the Crows' round one clash with Essendon at Etihad Stadium on March 23.

The 22-year-old had surgery on Tuesday on the fat pad in his heel, which was causing some irritation.

"Unfortunately, Riley started to feel some soreness in his ankle and it was decided that surgery was the best course of action," Crows' high performance general manager Matt Hass said in a club statement.

"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 played 19 of his 31 career games last year, including all three of the Crows' finals.

The ankle injury is an untimely blow after he turned heads on the track during the pre-season.

Knight claimed honours in the Crows' 2km time trial for first-to-fourth-year players when they resumed pre-season training in November.

He then finished third to veteran Sam Gibson and defender Jake Kelly when the players returned after the Christmas break in January.

Knight played across half-forward, averaging 14.7 disposals, four marks and four tackles per game last year, while kicking 13 goals.

He was also used in run-with roles where he could use his elite running capacity to shut down opposition midfielders.

Knight's injury opens the door for 2016 first-round draft pick Jordan Gallucci to force his way into the side.

Gallucci played just one game last year for the Crows, but has trained with the forwards during the pre-season after arriving at the club as an inside midfielder.

Knight joins captain Taylor Walker on the sidelines.

Walker will miss the JLT Community Series with a foot injury, but the club is optimistic he will be available for round one.