Port Adelaide small forward Angus Monfries will miss at least the next three weeks after suffering a hamstring injury at training.

Monfries returned from a 12-month anti-doping suspension this season after missing the entire 2016 campaign, but must now wait even longer before returning to AFL football.

The 30-year-old last pulled on the boots for Port Adelaide in round 22, 2015, and was set to feature early in the season after recovering from a shoulder injury suffered late last year.

Monfries is now the only serious concern for Port Adelaide's medical staff, as defender Jasper Pittard and ruckman Dougal Howard will be assessed during the week

“They have a few last checks to go, but all things going to plan they should get through this week,” Port Adelaide Head of High Performance Darren Burgess told portadelaidefc.com.au.

“It’s a really positive bit of news, particularly for ‘Dougs’ who’s obviously been out of action with that ACL.”

Hamish Hartlett should also return to the side ahead of the Showdown with Adelaide on Saturday night, after the half-back was a late withdrawal from Sunday's win over Fremantle through illness.