Power ruckman Matthew Lobbe will be sidelined for the next three months of the AFL season after suffering a knee injury in Port’s reserves side.

He joins the suspended former Bomber Paddy Ryder on the sidelines, leaving youngster Dougal Howard – who played just his second AFL game against the Tigers – to shoulder the ruck duties.

Key forward Charlie Dixon may also be required to help shoulder the load, although that would leave a gaping hole in a forward line that has failed to dramatically impose itself this season.

Lobbe was dropped back to the SANFL ahead of Port’s win over Richmond after an indifferent start to the season.

But the 27-year-old ruptured a posterior cruciate ligament against Sturt on Sunday, with the club electing not to put the ruckman in for surgery.

“The timeframes for recovery are pretty similar whether he has surgery or not,” Power high performance manager Darren Burgess said.

“It’s a fairly standard rehab program that he’ll do. He’ll be in a knee brace for about six weeks and will commence running in six to seven weeks.”

Meanwhile, Adelaide must contend without emerging defender Rory Laird, who is out of AFL action for up to three weeks because of a fractured toe, with swingman Ricky Henderson likely to take his place.

The half-back suffered the injury during Saturday’s home win over Fremantle and ended the game with his foot in ice.

Adelaide have impressed with their four-two start and Laird has been among their best players.

Further afield, GWS forward Devon Smith has joined veteran midfielder Ryan Griffen as long-term AFL casualties.

While the Giants are flying after three-straight wins, including last week’s demolition of Hawthorn, it is coming at a cost.

They confirmed yesterday that Smith would need knee surgery next week, sidelining him for at least two months.

After missing their round-four win over Port Adelaide, he returned for the successful away match against St Kilda and was again out of the side for the Hawthorn match.

Giants official David Joyce said they sought advice from a specialist last week and had several options to consider before deciding on the operation.

“The decision has been made to tidy up some of the cartilage in his knee that has been causing discomfort,” he said.

“We believe surgery is the best option at this stage of the season so that Devon can successfully return to the field later in the year.”

GWS had already flagged Griffen’s absence for five to six weeks thanks to a fracture in his back.

Griffen left training in obvious discomfort last week but, at the time, the Giants thought he was alright.

He was then a late withdrawal from the Hawthorn win.

-with AAP