sorry, but why then is she going to play the WCH??
Even as Harmotto made the team, USA coaches took a long time to make the decision to include her in the WCH team because she is coming back from injury. They'll be monitoring her match to match. She's been working very hard to come back and right now even a less-than-100% Harmotto still brings a lot to the USA team.
Managing an injury-risk player for a two-week WCH tournament for USA would be different from a 6-month season which probably factors into Piacenza's hesitation...