Port Adelaide veteran Travis Boak has been withdrawn from the Power's side to take on the GWSGiants at Adelaide Oval on Sunday afternoon.

The stalwart midfielder was ruled out of Sunday's important bout due to illness, with Francis Evans replacing Boak on Port's interchange bench. Riley Bonner has been added to Ken Hinkley's list of emergencies for the game.

The 35-year-old Boak is an unrestricted free agent at the year's end, having played 17 games this season thus far to put him in a position to potentially play on again in 2024.

After embarking on a club-record-breaking winning streak earlier in the season, Port Adelaide has lost its last four matches, falling to Carlton, Collingwood, Adelaide, and most recently Geelong in Round 21.

Still sitting comfortably inside the top four, Hinkley's men will want to improve their post-season seeding and aim to host a final in the first week of September.

On Sunday twilight, the Power faces a young, hungry Giants side looking to stamp their finals ticket.

The match is fixtured for 4:10 PM local time (4:40 PM AEST).