Port Adelaide vice-captain Zak Butters will be sidelined for at least six weeks after having knee surgery.

The dual All Australian had an arthroscopy on a knee which the Power said was to “tidy up a loose body found in the knee”.

“The injury was likely a result of a heavy knock to the knee, which also caused some bone bruising,” a club statement said on Friday.

Butters, who has won the past two best-and-fairest awards, was expected to be sidelined for six to eight weeks, the club said.

The dynamic midfielder reported soreness a day after last Friday’s match simulation against Adelaide, having copped a knock to the knee at training in weeks prior.

Power assistant coach Chad Cornes said he wouldn’t be surprised if Butters returned quicker than forecast.

“He’ll get on with business and be attacking his rehab as best as anyone would or could,” Cornes told reporters.

“He was a little down when he heard the news. But he’s a pretty positive guy who wants to get the best out of himself.

“He had the operation yesterday and it went well. He will do everything right in the rehab and might even surprise us and get back a little earlier.”

The Power’s premiership season opens against Collingwood at the MCG on March 15.