Boak will miss Saturday's Adelaide Oval game against North Melbourne because of an injury which has troubled the 36-year-old all season.
Boak is in ninth spot on the VFL/AFL games list with 376 - North Melbourne's Brent Harvey (432) holds the record.
And while the former Power captain is averaging 21 disposals from a wing this season, he's required injections to play three times.
"It's serious enough to give it a spell or require a spell," Power assistant coach Tyson Goldsack told reporters on Friday.
"He will miss this week.
"And he's getting old, so this early in the year you don't want to push it to breaking point. It was probably a good time for him to rest it up.
"Backs can be fickle. You can miss one week and be fine for next week - he has had three jabs in it for the year so it's just something we will continue to monitor week by week.
"He is the type of player that needs to be good on the outside for us and gives some run and some drive. He hasn't been able to do that ... copping knocks on it hasn't helped."
Port, now at 3-3 after consecutive wins over finals fancies Hawthorn and Sydney, are now also without first-year forward Tom Cochrane.
The 19-year-old, the first AFL player with Tourette's syndrome, Â has stress fractures in a foot and will be sidelined for months.
"It's flattening," Goldsack said.
"He has had it in the past, it's not new for him.
"But it's certainly not something you want to go through in your first year at the club, especially after playing some good footy at the top level.
'We feel for him."
Port also dropped Rory Atkins for the afternoon fixture against the Roos - the former Crow and Sun played his first AFL game in Power colours last week.
Jeremy Finlayson has been recalled as a forward - he was banished to the state league after round one when his experiment as a defender backfired in a 91-point belting from Collingwood.
The Power hold 10th spot ahead of hosting perennial strugglers North, who are stuck in 17th with one win and five losses - the past four in a row by margins of 82, 52, 65 and 36 points.
Kangas coach Alastair Clarkson made a selection statement by dumping experienced defensive duo Aidan Corr and Griffin Logue, while Zac Fisher (hamstring) was unavailable.
"Three defensive changes ... it's interesting they would go that way," Goldsack said of the Roos.
"But for us, it's work to our strengths regardless of who we are playing."