To accommodate the 2015 FIFA Women's World Cup, the league announced that it would reduce the season to 20 games while extending the calendar length into September and take a two-week break from June 7–19.

[1] Following a record-breaking 2014 season that saw the team winning the NWSL Shield and losing to FC Kansas City in the playoffs final, Head Coach and GM Laura Harvey expected minimal roster turnover entering into the off-season.

[5] Yanez, under her maiden name Goebel, played in Seattle on loan in 2014, scoring five goals and adding four assists while helping the Reign FC to a regular season title.

A day later, NWSL announced allocated National Team players for the 2015 season, with Reign FC defenders Stephanie Cox and Carmelina Moscato removed from the list.

[15] Wambach had already announced that she will not play this season to concentrate on preparing for the 2015 FIFA Women's World Cup,[16] and Harvey does not expect her to suit up for the Reign FC until 2016 at the earliest.

[17] The Reign FC headed into the regular season with a 19-player roster, with the one open spot reserved for Danish forward Katrine Veje's mid-season arrival.

[18] It includes 14 returners from last season's Shield-winning team, featuring league MVP Kim Little and fellow Best XI selections Jess Fishlock and Kendall Fletcher.