WEST Coast vice-captain Beau Waters has suffered yet another injury setback after he was ruled out of the Western Derby following a decision to send him for minor knee surgery. 

Waters will undergo an arthroscopy on his left knee that will rule him out for up to three matches. 

It has been a wretched year for the 2012 All Australian as he has managed to play just seven of 14 games due to various injury issues. 

Following a quad strain in round eight, West Coast elected to give the 27-year-old a four-week conditioning block before playing him again to avoid any further soft tissue injuries. 

But after playing the past three matches, Waters has been sidelined yet again. 

Jacob Brennan has also been ruled out of the derby with a groin injury.

It is the latest in a long line of injury woes for the Eagles with Scott Selwood and Shannon Hurn already sidelined for extended periods. 

Mark Nicoski has already had season-ending wrist surgery while promising youngsters Brant Colledge and Jeremy McGovern are also set for surgery this week. 

Colledge (ankle) and McGovern (hip) will both go under the knife in an attempt to get them ready for the pre-season. 

The news is not all bad though for the Eagles with Daniel Kerr, Luke Shuey, Sam Butler, Ash Smith, and Sharrod Wellingham all potentially available to return this week against Fremantle.