Chicago's Elena Delle Donne suffered a concussion Wednesday and is questionable for the All-Star Game this weekend.
Delle Donne fell to the court while going for a loose ball against Washington and left the game with about a minute left in the third quarter. She didn't return and the Sky lost 82-78.
"She's not nauseous now," said Sky coach Pokey Chatman, who confirmed the injury after the Mystics' team doctor examined Delle Donne. "She's groggy, headache ... moving gingerly. Hopefully she'll be OK."
Chicago is off until after the All-Star break. Delle Donne might be as well.
"The WNBA has their rules," Chatman said. "It's unfortunate, obviously for her, for us and also for Saturday. We have to make sure she gets back to healthy."
Mystics coach Mike Thibault thought Delle Donne's head hit the knee of a Mystics player while going for the loose ball. The 6-foot-5 star scored 12 points, going 2-for-15 from the field.
Delle Donne, the WNBA's third leading scorer at 18.6 points per game, is the first rookie to lead the All-Star voting. The All-Star Game is Saturday afternoon in Uncasville, Conn.
The Sky (12-5) entered with a season-high five-game winning streak.
Monique Currie finished with 14 points and Tayler Hill had 11 for the Mystics (9-9).
Atlanta 74, Connecticut 65: Angel McCoughtry had 22 points and the host Dream ended a four-game losing streak. Atlanta (11-5) held the Sun to 20 points in the first half, the lowest output by an opponent in the Dream's six-year history.