Port Adelaide have suffered an injury blow with important defender Tom Jonas to undergo knee surgery that will sideline him for a month.
The 27-year-old hurt his left knee in a tackle in the third quarter of the Power's win over St Kilda at Adelaide Oval on Saturday.
On Monday, the club announced that he required an arthroscopic procedure to remove a loose body in the joint.
Jonas has been a key contributor this season, playing 13 of a possible 15 games for the Power, who are fourth with an 11-4 record.
He is set to miss games against Fremantle (away), GWS (home), the Western Bulldogs (away) and Adelaide (away).
In other injury news, Jasper Pittard is in doubt for Sunday's clash with the Dockers at Optus Stadium.
Pittard missed the clash with the Saints with hamstring soreness and faces a fitness test.
Small forward Sam Gray also missed that match with an ankle strain, but is a chance to return in Perth.
Matthew Broadbent (foot) and Jake Neade (knee) require further assessment after hurting themselves playing for the Magpies in the SANFL.