With Fremantle leading by nine points in Saturday's decider at the MCG, Pearce was racing Brisbane opponent Logan Morris to collect a loose ball on the wing when he dramatically fell to the ground without any contact.
The star defender suffered a right Achilles injury, was assisted off the field and watched from the bench as Fremantle capitulated and Morris kicked the winning goal in the Dockers' 14.12 (96) to 12.17 (89) loss.
The Dockers confirmed the dreaded Achilles injury, which will likely also sideline Pearce for a large chunk of 2027 if it is fully ruptured.
"He's putting on a brave face," coach Justin Longmuir said.
"Everyone's devastated. I'm sure he's devastated, not only for today's result, but it looks like it might cost him a bit of time on the sidelines and another stint in rehab.
"But he can hold his head up high. Like he's led us so well across the course of the year, and stood up in really key moments to allow us to get here.
"Unfortunately it didn't go his way today and I feel for him on that front."
Longmuir said Pearce was "sore" coming into the game but adamant that didn't contribute to his injury.
Pearce, 31, was heartbreakingly close to becoming Fremantle's first premiership captain while the Dockers will wonder what might have been if they had their best key defender out there late.
"(We had to) reshuffle the deck chairs a little bit," Longmuir said.
"We had to play a bit smaller and we missed his leadership across the back end of the game and clearly missed his leadership late. He gives us so much in that aspect of the game.
"Feel really sorry for him. He would have loved to have been out there with his teammates, and we definitely missed him."
