Sydney veteran Luke Parker is facing an extended period on the sidelines after requiring surgery on a broken arm sustained in last week's match simulation session against GWS.
The injury, which occurred in the final term of Thursday's match, has required the 31-year-old to go under the knife and places him out of action for the start of the 2024 season.
The Swans are set to meet with specialists later this week to determine the full extent of Parker's setback, which could be extensive.
Parker has been a durable asset for the Swans over the past decade, playing under 20 games in a season on just two occasions since the start of 2013.
The premiership Swan is just 17 games away from becoming the fifth Sydney player to reach the 300-game milestone.
Sydney are already without captain Callum Mills for what will likely be the opening half of the coming season following an off-season shoulder injury.
The Swans are scheduled to face Brisbane later this week for their final pre-season match before turning their attention to Opening Round, where they'll host the season opener against Melbourne at the SCG on Thursday, March 7.