Pugh, who turned 19 years old on April 29, finished high school a year ago but sat
out the fall semester at UCLA to play for the USA at the Under-20 World Cup. She has made 22 appearances and scored four goals for the USA since she received her first call-up in January 2016. She
played for the USA at the 2016 Olympics in Brazil.
Pugh isn't the first American to skip college. Fellow Coloradan Lindsey Horan signed a six-figure contract with French club Paris St. Germain in 2012 instead of enrolling at the University of North America. There was no U.S. women's pro league in 2012. Horan joined the NWSL's Portland Thorns in 2016.
"I am very excited to begin my career in the NWSL and with the Washington Spirit," said Pugh. "Being part of a professional team will allow me to grow and develop as a player, and I look forward to helping the Spirit win championships."
There was much speculation the 2016 Olympian didn't want to play in Washington, but the Spirit acquired the first position in the NWSL Distribution Ranking Order via a series of offseason trades with Orlando and Boston and held on to that position.
"This is a monumental moment for our club and the NWSL,” said Spirit head coach and general manager Jim Gabarra. “We are extremely humbled and grateful for the opportunity to develop such a talented player. We look forward to having Mallory join the Spirit family."
Four players from the 2016 U.S. U-17 Women's World Cup team -- Jaelin Howell (Real Colorado), Sophia Smith (Real Colorado), Ashley Sanchez (So Cal Blues) and Brianna Pinto (CASL) -- have trained with the national team but none has been capped.
Pugh played -- and scored -- in a friendly against Ireland after her first camp.