Adelaide have confirmed defender Josh Worrell's return timeframe from a recent hamstring setback remains up in the air, with the club to take a cautious approach in aiding the young backman back from the injury.

Worrell re-aggravated a previous hamstring concern during the Crows' opening pre-season match against Fremantle, with the setback placing the 21-year-old's plating prospects for Round 1 in doubt.

Adelaide confirmed on Tuesday that Worrell's chances of a Round 1 showing are still uncertain as they look to assess how the defender reacts to treatment on his hamstring.

“Scans showed a hamstring injury and we will take a cautious approach with Josh but a timeline for his return to training is really dependent on how he responds to treatment in coming weeks,” Adelaide high-performance boss Darren Burgess said in a club statement.

Worrell's setback sees Matthew Nicks' defensive depths take another hit, with Andrew McPherson already sidelined with a knee issue.

Worrell managed four games at AFL level last season after making his debut the season prior.

Meanwhile, draftee Billy Dowling will miss the beginning of the home and away season after hurting his right foot during last week's hitout against West Coast.

The teenager, who joined Adelaide as the 43rd overall selection in last year's draft, is set to miss the next 3-5 weeks of action due to the injury.

“Billy had scans which have shown a joint-related issue in his foot,” Burgess confirmed.

“It's an unusual injury that will keep him off legs for at least a week but he will be reassessed after that and we anticipate a return to full training with the main group in 3-5 weeks.”

Adelaide Crow Billy Dowling (Image via Adelaide Media)

An inside midfielder, Dowling will likely be reintroduced through the SANFL before being seen as a viable selection option for Nicks to consider.

Adelaide will open their 2023 home and away campaign against GWS at Giants Stadium on Sunday, March 19.