Megan Surgery

I was surprised when I read this on the US Soccer Web Site about the USA match with Germany. Does anyone know details about Megan's surgery and how long it will keep her out of action? From the timing, sounds like it could have been a planned surgery.

"Averbuch, normally a central midfielder, put in 60 solid minutes on the flank after 21-year-old Tobin Heath fell ill yesterday with flu-like symptoms and could not play. Heath would likely have started at left outside midfield, a spot occupied this year mostly by Megan Rapinoe, who missed this trip due to minor knee surgery."
Here is the link to the article
http://www.ussoccer.com/News/Womens-National-Team/2009/10/US-Defeat-Germany-1-0-in-Augsburg-Germany.aspx