SYDNEY captain Callum Mills has suffered a hamstring strain that will keep him out of full training until after Christmas.

Mills, 28, was tackled in a contested drill and fell awkwardly at training on Wednesday.

Scans have confirmed a minor hamstring strain, as first reported by AFL.com.au's Cal Twomey.

Mills has endured a torrid injury run in recent years and was limited to just 12 games in 2025.

He played just seven games in 2024 and missed the Grand Final after a hamstring strain in semi-final week.

His start to that year had been delayed after he suffered a torn rotator cuff while playfully wrestling with then-teammate Jacob Konstanty during the Swans' end of season celebrations in late 2023.

The Swans will open the 2026 season with a clash against Carlton at the SCG on March 5.