Butters, among the competition's best midfielders, sprained his right ankle 10 minutes in to Port's 13.14 (92) to 8.5 (53) victory at Alberton Oval on Friday night.
The brilliant on-baller went to push off his right leg but rolled his ankle without any contact from an opponent.
"He rolled his ankle so we took him out; we just didn't want to take a risk," Port coach Ken Hinkley told Fox Sports.
"He's not the sort of player you want to mess around with."
Butters didn't appear overly troubled his injury, which wasn't iced prior to him walking off the oval to the Power's headquarters at quarter-time.
Port's new vice-captain, who finished fourth in last year's Brownlow medal, has more than two weeks to recover ahead of the Power's premiership season opener against West Coast on March 17.
But the 23-year-old playmaker's injury took some gloss of a polished performance by the Power.
Port's new captain Connor Rozee (26 disposals, one goal, seven tackles) and halfbacks Ryan Burton (30 touches, 13 marks) and Dan Houston (26 possessions) were superb while Willie Rioli kicked three goals.
The Power's new-look defence featuring recruits Brandon Zerk-Thatcher (nine marks) and Esava Ratugolea (eight marks) was also miserly.
Fremantle veteran Nat Fyfe, relishing his return to the midfield, producing a stellar 10-disposal opening term and finished with 26 touches and five clearances.
Fyfe's on-ball colleague Hayden Young was a stand-out with two goals and 26 possessions, Caleb Serong gathered 29 touches and stalwart Michael Walters kicked two majors.
Despite Fyfe's early brilliance, the Power led by one point at quarter-time, with ruck recruit Ivan Soldo kicking the opening goal of the game after taking a mark just 20 seconds in.
In the second quarter, Port kicked five goals to one in a slick 14-minute burst to create a 26-point break, before a pair of snapped goals from Freo's Young helped reduce their deficit to 14 points at halftime.
The Power accelerated again in the third term, scoring 4.6 and  keeping the Dockers - who rested influential lead ruckman Sean Darcy for the last half - scoreless.
Port advanced to a 44-point lead at three quarter-time and were outscored three goals to two in the last term.
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