Port Adelaide will be without co-captains Tom Jonas and Ollie Wines for their Showdown clash with Adelaide on Saturday night.

Jonas has been ruled out for the third straight game as he continues to battle a calf strain, while Wines has a small fracture of his fibula, and will miss around a month of football.

Wines is set to return for the Power after their round 12 mid-season bye.

Veteran midfielder Brad Ebert was concussed during his side's loss to Collingwood last Friday night, and will miss the Showdown.

In some good news for the Power, Matthew Broadbent will return for his first game since the Power's thrilling win over St Kilda back in round 19, 2017.