Misfiring Port Adelaide have lost star onballer Robbie Gray in a massive blow for Saturday night’s must-win AFL match against Richmond.

Gray suffered a hamstring injury at Wednesday training and is expected to be out of action for two to three weeks.

The two-time All Australian has been easily Port’s best player so far this season as they labour with a 2-3 record.

Chad Wingard is also out with delayed concussion and they dropped ruckman Matthew Lobbe among five changes.

Karl Amon was the other omission and Jackson Trengove is suspended.

Port recalled Jared Polec, Brendon Ah Chee, Jarman Impey and Dougal Howard.

Nathan Krakouer is also back for his first senior game of the season after serving his six-week club suspension.

Saturday night’s match is also crucial for the Tigers, who are having another poor start to a season at 1-4.

They will regain vice-captain Brett Deledio for his first game of the season and recalled Shaun Hampson to ruck with Ivan Maric.

Alex Rance (suspension) is a major loss and Jacob Townsend was dropped.

Injury-plagued Gold Coast made four changes for Saturday night’s tough away match against Geelong.

They lost Michael Rischitelli (shoulder) and Adam Saad (hip), but have recalled Dion Prestia despite concerns about his shoulder.

Mackenzie Willis will make his debut and Henry Schade and Ryan Davis return, with Luke Russell and Callum Ah Chee the other omissions.

The Cats brought in defenders Lachie Henderson and Jed Bews for Tom Ruggles and Cory Gregson.

St Kilda have left out Paddy McCartin for Saturday’s match against Melbourne, meaning the two top picks of the 2014 draft will not play against each other.

Melbourne’s Christian Petracca, the second pick behind McCartin, will finally make his senior debut as they again dropped Angus Brayshaw.

The Saints also dropped Tom Lee and Jack Lonie for Tim Membrey, Blake Acres and Jade Gresham.

Fremantle captain David Mundy is back from his calf injury and Connor Blakely will play his first game this season on Saturday against Adelaide, who are unchanged.

They come in for injured stars Nat Fyfe (leg fracture) and Michael Johnson (hamstring).

Hawthorn lost Will Langford (corked quad) and dropped Billy Hartung for Saturday’s big match against GWS, with Kieran Lovell named for his debut and Daniel Howe back in the side.

Devon Smith has a knee injury and the Giants replaced him with Rhys Palmer.

Friday night’s match of the round between North Melbourne and the Western Bulldogs will feature only one change, with Fletcher Roberts replacing Matthew Suckling (ankle) in the `Dogs lineup.

As expected, Travis Varcoe’s hamstring injury means he will not play for Collingwood on Sunday against West Coast.