PORT Adelaide captain Domenic Cassisi is available for Sunday's match against Fremantle despite scans revealing a depression in his frontal sinus.

Cassisi clashed heads with Hawthorn's Jordan Lewis in the third quarter of the weekend's victory and though he suffered concussion, later returned to the field with his head bandaged.

The club confirmed that Cassisi's sinus depression was minor and that he could wear a helmet for the game as precaution.

Cassisi has played 17 of the Power's 18 games this season. He was suspended for the round four match against the Hawks.