The LA Galaxy plays soccer right down the street, at StubHub Center, in Carson. The seating capacity is only 27,000, but it is the largest soccer specific stadium in US Major League Soccer. I went to an NFL Futures game there, a few years ago. It’s a really nice venue.
By largest you mean roughly 1/3 the size of the unrestricted seating capacity of CenturyLink in Seattle (67K), home of the Seattle Sounders, who AVERAGED over 43K every season??? (which is above their restricted capacity of 38K). Before you get all huffy about the Galaxy being the primary tenant ... part of how CenturyLink was sold was based on the inclusion of MLS.
http://en.wikipedia.org/wiki/Major_League_Soccer_attendance