Walters, who is currently sidelined by an ankle injury, will stay with the Dockers until at least the end of 2016 after extending his current deal by a further two years.
The 22-year-old has emerged as one of the AFL's best small forwards this year, booting 19 goals over the first seven rounds before sustaining the injury against the Sydney Swans.
Walters' career was hanging by a thread early last year when he was banished to the WAFL for failing to meet Fremantle's fitness standards.
But he worked his way back into favour by round 16 and played a pivotal role in Fremantle's charge to the semi-final.
The 177cm speedster has played 29 games since being taken with pick No.53 in the 2008 national draft, and could be back in action for the club's June 15 clash with the Brisbane Lions at Patersons Stadium.
Silvagni was reported for rough conduct in Sunday's 90-point win over Melbourne after unleashing a high tackle on Nathan Jones.
Jones was left bleeding by the hit, but the panel viewed the contact as accidental.
Silvagni rolled his ankle later in the match and will be further assessed ahead of Saturday's clash with Adelaide at AAMI Stadium.
Skipper Matthew Pavlich was on track to return against the Crows, but Fremantle are set to err on the side of caution by giving the 282-game veteran another fortnight to recover from plantaris surgery.
Fremantle have the bye next week, and coach Ross Lyon said the six-time All Australian was more likely to feature against the Lions.
Stephen Hill is set to return from injury against Adelaide, bolstering Fremantle's midfield stocks in a game that could prove vital in the top-four hopes of both sides.
The Dockers currently occupy fourth spot on percentage from the Swans, but the Crows (5-4) are just six points behind.
Fremantle have coped tremendously well with their heavy injury toll this year, posting six wins and a draw from their first nine rounds, despite losing key players Aaron Sandilands, Jon Griffin, Kepler Bradley, Anthony Morabito and Pavlich to serious ailments.
Griffin and Bradley won't appear again this season, while Sandilands (hamstring) is at least a month away from resuming.
But the recent return of Zac Clarke has given Fremantle's ruck stocks a timely boost, with Jack Hannath offering vital back-up.
Clarke has averaged 15 possessions and 24 hit-outs over the past fortnight, but faces a stern challenge against Adelaide big man Sam Jacobs this weekend.
