The 22-year-old will require to wear a knee brace for close to a month after suffering the injury and is now set to play catch-up as the Dockers prepare for the 2021 season.
Fremantle football boss Peter Bell revealed the extent of Darcy’s injury and that the Dockers’ tall will be re-assessed in the coming weeks.
“Scans have shown that Sean has damaged his arcuate ligament in his left knee,” Bell told the club website.
“The current advice is he will need to wear a knee brace for the next two to four weeks.
“This means Sean will miss a number of weeks of pre-season training and the injury will be reassessed once he is out of the knee brace.”
The Dockers are scheduled to face Melbourne for their opening pre-season clash on Friday, February 26 at Fremantle Oval before a match against the Eagles on Sunday, March 7.
Fremantle will face the Demons again to kick-off their 2021 premiership campaign on Saturday, March 20 at the MCG.