"It's more the fact we just don't want to lose," said McGregor, knowing the Crows won three duels with the Power last season.
"We want to play good footy and win games. It doesn't matter who it's against. It's not really having a dominance thing. Every time we play Port, we're going to want to beat them, and every time we play Collingwood or whoever, we're going to want to win.
"We've all been looking forward to this for a few months just to see how our plays go in a real game with real competition.
"Our confidence is pretty high because we know we're playing some pretty good footy and we know we've done a really good pre-season. We know we're where we want to be at this time of the year. That's the main thing for us."
Asked whether there had been a time when the Crows might have thought they couldn't beat Port, McGregor said: "No, I honestly never went into a game feeling like that, and I'm sure none of the players with me ever really felt like that.
"Every game we played, we thought we were a good chance. But just for a while there, they were probably just better than us. We managed to play some good footy last year and hopefully that can keep going.
"I definitely wouldn't write them off as not having a good side. They've got some really good players and they'll be very dangerous this year, too.
"It's always good to play against Port. The rivalry is there. There's no point trying to mask it. It's great playing against them and we'll enjoy it, but we're looking forward to the next four weeks. It's going to be a good test for us.
"The next four weeks are very important. We're building on stuff - our forward structures and midfield - and we've got a lot of younger players coming in. We're seeing it more as a four-week block of trying to improve and get ready for round one than actually just one game."
McGregor, equally at home at centre half-back or centre half-forward, kicked five goals from centre half-forward against Norwood last Friday night.
Asked where he hoped to play more this season, he said: "I'm enjoying it up forward at the moment. As long as I can stay up there and get a kick, I'm happy to play there, but obviously I'm happy to do the job, whatever Craigy wants me to play. As long as I'm out on the ground most of the time, I'll be happy."
At least six Crows are unavailable this week - Nathan Bassett, Scott Stevens, Ben Hudson, Scott Welsh, Chad Gibson and Michael Doughty.
Adelaide's injury list is:
Nathan Bassett (shoulder) full training in March
Scott Stevens (foot/shoulder) full training in March
Chad Gibson (groin) full training in March
Ben Hudson (knee) to be confirmed
Scott Welsh (stress fracture of leg) end of March
Mark Ricciuto (groin) test
Andrew McLeod (glute/hamstring) available
Graham Johncock (gastro) available
Jason Torney (gastro) available
Tyson Edwards (leg soreness) available
Matthew Clarke (leg soreness) test
Ben Hart (leg soreness) test
Michael Doughty (knee) resumes training this week
