The decision was made to rectify the problem now to give Harnwell ample time to recover prior to the start of the Hyundai A-League home and away season and ensure a clean bill of health during the upcoming campaign.

Harnwell has been on light duties at training in the past few weeks and was restricted in his movement during the club’s recent practice matches. He didn’t join team mates for the club’s two-match pre-season tour of Indonesia which kicks off on Sunday evening against Super League side Persik Kediri.

Harnwell will undergo the procedure early this week and is already mapping out his rehabilitation to ensure he is ready for Perth’s first match of the season against Adelaide on Sunday 17 August.

The striker told his club's official website: "I’ve been told that this is something that could have been around for a few years and unfortunately it has been irritated somehow and now we need to address it.

“The decision was made to get it done as soon as possible and I’d rather it happen now than midway through the year and try to manage it for six months."

Despite this slight setback Harnwell is excited about the upcoming season and says there is a genuine enthusiasm and belief amongst the players that this will be a positive season for the Glory.

“The atmosphere around the club has been terrific and the new training ground is great, everyone is keen to be at training and we’ve got a great group of lads that all want to play consistent, winning football.

“I’d expect to be back playing at full pace within five to six weeks and my aim is definitely to be ready for the start of the season. I’m determined to be out there doing everything I can for the team from round one onwards,” Harnwell said.