Trengove dislocated a finger on his right hand in the first quarter of the clash and was immediately subbed out of the game.
Medical staff were unable to put the finger back into place on the sidelines and when Trengove emerged from the rooms later his right hand was heavily strapped.
[ Related: Quarter by Quarter Match Report ]
"He's hurt his finger and if he had stayed out there he might have hurt it more," Power coach Matthew Primus said in relation to Trengove's subbing in the opening term.
"That was the call from the medical staff, just didn't want to take any risks there."
Butcher was reported for rough conduct against Melbourne's Colin Sylvia in the final quarter, after a late mid-air collision.
Sylvia landed heavily on his back and was stretchered from the ground before being taken to hospital for scans.
The incident sparked an all-in melee, with every player on the field involved, but it was Butcher who found himself on report.
"Butch plays the ball…I'd like to have another look at it before I comment on it, but Butch plays the ball and I'm sure that's what it probably looked like," Primus said of Butcher's report.
Danyle Pearce was on fire from the word go, finishing with 33 disposals and setting up countless attacks with his work across half back and through the middle.
"I'm not sure we'll get those performances from him every week, we'd love to, but the opposition will put some attention into him," Primus said.
"We're happy for him to have the ball as much as he can, he's one of those players we want to get the ball in his hands."
[ Related: We Win, You Win - 30% off online at the Power Megastore until Tuesday ]
Kane Cornes proved there's still juice left in his tank, instrumental in the middle with 31 touches, as was Matthew Broadbent, Travis Boak and Brad Ebert.
Jay Schulz again fired up forward with three goals.
For the Demons, ruckman Mark Jamar was the clear stand out with a dominant effort in the ruck.
Jamar finished the game with 45 hitouts, while Nathan Jones kicked two goals and racked up 22 possessions.
Brent Moloney, Aaron Davey and James Frawley were also in fine touch for the visitors.
After slotting the opening five goals against Fremantle last week, the Power again bolted out of the blocks with a six-goal-to-two first term.
Despite Jamar dominating the ruck with 14 hitouts for the term, Port were clearly winning the midfield through Boak, Ebert and Cornes, while Pearce was instrumental running off the half back flank.
The Demons hit back in the second, with goals to Mitch Clark and Jones and when Ricky Petterd goaled the margin had been cut to 20 points.
But as John McCarthy's game heated up the Power continued to dominate around the ground, and they entered the main break with 148 uncontested possessions and a 27-point lead.
That extended to 35 by the final change, with young Aaron Young booting two goals for the term while Pearce, Cornes and Cameron O'Shae continued to find the ball at ease as did Robbie Gray.
Port continued to pull away in the last, rounding out an impressive pre-season.
Primus said the win had given his side a platform to 'attack the season in a good, competitive, committed way'.
"The players have lifted their intensity every week…does that mean you're going to win 21 games or one game? I don't know, time will tell," he said.
"I couldn't be more happy with how we're prepared to start the season and that's the most exciting thing."
PORT ADELAIDE 6.3 8.7 13.7 17.10 (112)
MELBOURNE 2.1 4.4 7.8 9.10 (64)
GOALS
Port Adelaide: Schulz 3, Broadbent, Ebert, Pfeiffer, Young 2, Gray, Logan, McCarthy, Stewart, Thomas, Jonas
Melbourne: Clark 3, Jones, Blease 2, Petterd, Davey
BEST
Port Adelaide: Pearce, Ebert, Cornes, Gray, Boak, Broadbent
Melbourne: Jamar, Jones, Davey, Frawley, Moloney, Rivers
INJURIES
Port Adelaide: Trengove (finger)
Melbourne: Howe (cut head), Silvia (back)
Reports: John Butcher (rough conduct)
Official crowd: Approx. 2500 at AAMI Stadium
