Speaking to the USWNT media channel, the 47-year-old said, "I am sure everybody can understand when you have been associated with a club for almost 12 years. A club built from the bottom up, become a family, become so much of my own identity. Without question, it pulled my heartstrings because I care so much for the players and everybody that I have built a relationship with. But I am all about challenge and we won a lot at Chelsea, I am very proud of that.
"And I am proud of the fact that I could leave that club in a better place, the one that I hope continues to compete. But for me, the challenge of competing for World Cups, for Olympics, and the dream of coaching a team that I have always wanted to get the opportunity to do, simply couldn't turn it down."