Tippett developed soreness in his hamstring after training on Wednesday and scans have revealed a minor strain.
Caretaker coach Mark Bickley said he expected the Crows' leading goalkicker to miss at least a fortnight.
"Kurt won't play and there's rarely such thing as a one-week hamstring," Bickley said on Friday.
"We haven't been relying on Kurt to kick our winning score … we haven't been scoring that well at all, and I don’t think Kurt has kicked a goal in the last two weeks.
"While it's a blow … one of the things we've been guilty [of], and that's been talked about is that we go to Kurt too much.
"If anything, it perhaps gives us a little bit [of] unpredictability about the way we go into our forward line."
Tippett and Brad Symes (jaw) are the only confirmed exclusions from the team that lost to St Kilda by 103 points last week, but Bickley revealed both Taylor Walker and rookie-listed onballer Aidan Riley would play against the Power.
Walker hasn't played since injuring his knee against the Brisbane Lions in round 10, while Riley will become the first player from Wollongong to play AFL when he makes his debut on Sunday.
"It's fantastic for Aidan," Bickley said.
"He's a really good story for our footy club, (as a player) out of the NSW scholarship group of players.
"He's showed some really good form in the SANFL. He's a rugged, robust young fella and we think the Showdown style [of game] will suit him."
Showdown XXXI will be Bickley's first game in charge of the Crows since taking over from long-serving coach Neil Craig, who bowed to mounting public pressure and resigned on Monday.
Bickley admitted there had been a temptation to make sweeping changes to the team that lost to St Kilda by 103 points last Friday night, but said the majority of players involved in the embarrassing loss would be given a chance to "make a statement" against Port Adelaide.
"There'll be some players, who get an opportunity [for redemption] and that's probably more out of necessity because we could probably have dropped 18 blokes after last week," he said.
"We can't do that, so some of them you have to trust that they will show a response.
"Sometimes, when you plummet to the depths you learn a lot about your players and you see who can respond and who can't."
Adelaide is optimistic Craig's resignation will have the intended effect, and relieve some of the pressure that had transferred from the embattled coach to the players throughout the course of the club's disappointing season.
Bickley was hopeful the Crows would be able to reproduce the attacking brand of football they displayed in the first half against Essendon just two weeks ago, in the twilight clash on Sunday.
"The club needs to respond from last week. It's really important for our club," Bickley said.
"What we're asking the players to do is to trust their instincts, not be frightened to make a mistake and have a bit more of that free-flowing nature that I've seen them play with.
"We'll make some positional moves and I'll appeal to them to have a change in attitude, but whatever happens on the weekend there's going to be some residual from what's been there in the first two-thirds of the year.
"Certainly, if we win I won't be taking the credit for it."
Katrina Gill covers Adelaide news for afl.com.au. Follow her on Twitter: @AFL_KatrinaGill
