Pavlich kicked two goals from 21 possessions in his side's 30-point win over a plucky St Kilda in Perth on Sunday, while Sandilands (six disposals, 11 hit-outs) got some much-needed game time before being subbed off in the third term.
The pair represent the final pieces of the puzzle in Fremantle's bid to win this year's premiership.
But the Dockers will have to make do without their rock in defence against the Eagles after McPharlin tweaked his calf in the 15.10 (100) to 11.4 (70) triumph over the Saints.
Fremantle coach Ross Lyon is hopeful McPharlin will only miss one week, but scans will determine the extent of the damage.
Lyon said either Alex Silvagni or Peter Faulks would replace McPharlin against the Eagles, who boast marking targets such as Josh Kennedy, Jack Darling, Nic Naitanui and Dean Cox.
The Dockers remain just percentage adrift of fourth spot, but they did it the hard way against St Kilda, whose relentless tackling and ferocious pressure stunned Fremantle in the opening half. The Saints led by five points midway through the third quarter, but two long-range goals from Pavlich within the space of a minute swung momentum Fremantle's way.
Goalsneak Hayden Ballanytne kicked five goals in a best afield display, with four of those goals coming in the opening half when the Saints were dominating.
Lyon said he was disappointed with his team's first-half effort, describing it as the "elephant in the room".
He also conceded Pavlich, who hadn't played since round three, and Sandilands, who was playing his first game of the season, were a tad rusty.
"It's a hard business when Aaron got a Bronx cheer when he gloved one," Lyon said.
"But I think they'll be better for the run."
Jack Steven, Leigh Montagna and Lenny Hayes were terrific for the Saints, while recalled forward Lee booted three goals in the absence of injured skipper Nick Riewoldt.
Riewoldt, who was rested against the Dockers due to soreness in his knee, said he was "locked in" to take on Carlton next Saturday night.
Fellow Saints forward Stephen Milne, who is facing four charges of rape, and Justin Koschitzke could also return against the Blues.
St Kilda won the tackle count 77-46 against Fremantle, but coach Scott Watters said they needed to sustain their effort for longer periods.
"Our efforts from first quarter to fourth quarter slowly taper at the moment and we're aware of that," Watters said.
"We are striving for competitiveness every week, but until you have got three, four, five pre-seasons into a large proportion of your group, you are not going to get that.
"But we will keep striving for it."
Which Fremantle players deserve your 3-2-1 votes? Click here to vote.
FREMANTLE 3.1 6.2 11.6 15.10 (100)
ST KILDA 2.2 7.3 9.3 11.4 (70)
GOALS
Fremantle: Ballantyne 5, Pavlich 2, Mundy 2, Mayne 2, Mzungu, De Boer, Walters, D Pearce
St Kilda: Lee 3, Dennis-Lane 2, Saad 2, Saunders, McEvoy, Dal Santo, Jones
BEST
Fremantle: Ballantyne, Mzungu, Mundy, Fyfe, C Pearce, Spurr, Crowley
St Kilda: Montagna, Steven, Hayes, Jones, Lee, Ray
INJURIES
Fremantle: McPharlin (calf)
St Kilda: Nil
SUBSTITUTES
Fremantle: Tom Sheridan replaced Aaron Sandilands in the third term
St Kilda: Terry Milera replaced Nathan Wright in the third term
Reports: Nil
Umpires: Farmer, Pannell, Fisher
Official crowd: 34,064 at Patersons Stadium
