Fremantle youngster Cooper Simpson is set for a lengthy stint on the sidelines after scans confirmed a "high-grade" injury to his AC joint, which included displacement of the clavicle.
Simpson injured his shoulder in the win over Port Adelaide at Optus Stadium, and will be sent in for surgery on Monday.
The 20-year-old, after debuting last year against the Western Bulldogs, returned to the senior side against Collingwood in Round 9, before playing the past two victories over GWS and the Power.
"This is a relatively rare injury, and the best intervention is to head in for surgery," EGM of Football Joe Brierty said.
"We will know more on timeframes post the procedure, but at this stage we expect Coop to be back playing in around 10 weeks.
"Obviously, it's disappointing for him after returning to AFL footy. He put his body on the line for the team, and it's those trademark actions that we value.
"We will support him through this setback, and we know Coop will work diligently in his recovery."
Fremantle coach Justin Longmuir was full of praise for the young defender,
"Firstly, it's real growth in his (Simpson's) game to be able to own the line of the ball like he did and commit to that contest," Longmuir said post-game.
"Footy puts you in those really vulnerable situations where you just have to go for the team, and I really loved his endeavour and commitment.
"When your youngest players are doing that, it's a good sign."
Simpson's injury news comes as the Dockers are weighing up whether to challenge captain Alex Pearce's three-match suspension for his collision with Power forward Darcy Byrne-Jones.
Occurring in the second quarter, Bryne-Jones came off second best when coming into contact with Pearce in a marking contest. He was concussed and subbed out for the remainder of the match, and will miss the following 12 days as he enters protocols.
The MRO graded the incident as careless conduct, severe impact and high contact, with the Dockers having until 12pm (AEST) on Tuesday to decide whether to accept or challenge the ban.
Fremantle will face Gold Coast in Round 12 before entering their mid-season bye.
