Last year at the 2015 Women's World Cup, the WNT defense kept the United States in it long enough for the offense to start clicking and bagging goals. That back line of Meghan Klingenberg, Julie Johnston, Becky Sauerbrunn, and Ali Krieger seemed impenetrable, imperturbable, unbothered by attempts to get through to Hope Solo.
That defense has shown some cracks in 2016, but there still aren't too many questions of the back line going into the Olympics. The primary big question is whether Kelley O'Hara or Ali Krieger will start, while the secondary and somewhat less important question is who will go as the third center back.