The Red Stars released defender Ifeoma Dieke and forward and Naperville native Michele Weissenhofer.
"We're excited about the additions of Nikki and Elise to our roster," Red Stars coach Omid Namazi said, in a release. "Nikki is a dynamic attacking player who will add another dimension to our game. Elise brings an attacking dimension to the left back. ... Obviously releasing players is very difficult, and we'd like to thank Ifeoma and Michele for their contributions to the Red Stars."
Washington has been placed on the team's 18-player first team roster and is questionable to play for Sunday's game against the Atlanta Beat. She has made strong progress recovering from an ACL injury during her final season at North Carolina.
Weber, who was drafted by Athletica in 2009 and played at Notre Dame, has been named to the developmental roster. WIth Weber, St. Viator won state championships in 2002, 2003 and 2005.