Former Power skipper Travis Boak will not play in this Saturday's pivotal clash with Brisbane at the Adelaide Oval.
The veteran midfielder has caught an illness and has been withdrawn from the team's lineup, replaced by youngster Josh Sinn.
It's a considerable loss for Port Adelaide, Boak having played 11 of their matches in the lead up to Round 15 and performing admirably outside of the Butters, Rozee, Horne-Francis limelight.
His two week stretch of 26 disposals and seven inside 50s against Hawthorn, before a 25 disposal, 12 mark display against North Melbourne has him highly regarded within the Alberton camp, and a crucial cogg in key matches like this one against a red-hot Brisbane.
He is not the only listed player to be ruled out with illness this week, Docker Brandon Walker being withdrawn from Fremantle's equally pivotal match against Gold Coast at Optus Stadium.
He will be replaced by forward Pat Voss, far from a like-for-like replacement for the rebounding defender.
21-year-old Walker will be missed in the Docker defence, having proven himself a mainstay with his 12 appearances this season.
His best performance thus far came in a Round nine loss to league-leader Sydney, whom he collected 19 disposals, four marks and 92 SuperCoach points against.
Both sides will want to perform well despite their late absentees, coming off disappointing losses that were heavily scrutinised during the week, now heading into season-defining matches to prove their finals credentials.