Darcy made his return to play on Saturday against Geelong following a period on the sidelines due to a lung issue, with the young Bulldog 13 disposals, nine hitouts and six scoring shots against the Cats over the weekend.
Following the 58-point win, Darcy reported pain in his jaw and underwent scans on Monday to better understand the soreness.
The club confirmed on Tuesday that a small fracture was located in his jaw. Following specialist advice, Darcy will undergo surgery and be sidelined for at least three weeks as part of his recovery.
"Following a knock in Saturday's VFL game, Bulldogs forward Sam Darcy reported some soreness in his jaw," a club medical update read.
"Precautionary scans yesterday have identified a small fracture in his jaw bone.
"After consultation with specialists, it has been determined that an operation to stabilise the fracture will accelerate his recovery and minimise risk of ongoing issues.
"Sam's return to play plan will become clearer after the operation, but is expected to make a return to playing soon after the club's mid-season bye."
Darcy played in the Western Bulldogs' two opening games this year before a further four matches with Footscray in the VFL prior to 19-year-old suffering breathing concerns due to a hole located in his lung.