UNCASVILLE, Conn. — Mike Thibault, the coach of the Washington Mystics, carefully watched his star player, the W.N.B.A.’s 2019 most valuable player, Elena Delle Donne, as she shot around about 90 minutes before Game 3 of the W.N.B.A. finals on Sunday afternoon.

“I woke up this morning with no better answers than when I went to bed last night,” Thibault said of Delle Donne’s availability, which was compromised by a herniated disk. The injury was discovered after she left the floor with a little more than three minutes gone in Game 2.

But 35 minutes before game time on Sunday, Thibault got the news he had been hoping for: Delle Donne could play.

What followed was anything but vintage Delle Donne, who took only six wincing shots, but made five. Her teammates rallied to the cause and defeated the Connecticut Sun, 94-81, taking a two-games-to-one lead in the best-of-five finals.