WASHINGTON -- League MVP Elena Delle Donne did not return to the court after leaving because of back spasms in the first quarter of the Washington Mystics' 99-87 Game 2 loss to the Connecticut Sun in the WNBA Finals on Tuesday.
The best-of-five series is now tied 1-1.
Delle Donne will undergo an MRI on Wednesday, Mystics coach Mike Thibault said. She played just 3 minutes, 28 seconds before heading to the locker room, and the team announced in the fourth quarter that she would not return. She was not in the locker room after the game and didn't address the media.
Thibault said that this scenario -- his best player getting injured during the Finals -- has been his nightmare. He added that the injury "didn't look good."
Thibault said that when Delle Donne went up for her first layup, her back "grabbed on her," and she immediately asked to be subbed out.
"We'll see. But I have no idea right now," Thibault said. "And we won't have anything probably for a couple days until we see what the tests show and what treatment looks like."
One positive is that Game 3 in Connecticut is not until 3:30 p.m. ET Sunday.
"I didn't look forward to having four days between games," Thibault said. "But right now, that looks like a benefit."
Delle Donne led the Mystics with 22 points in Sunday's 95-86 victory in Game 1. She spoke to the media Saturday and again Monday before Mystics practices and didn't indicate that she was having any physical problems. But ESPN's Holly Rowe reported that Delle Donne didn't practice much Monday because of a back issue. Thibault said Monday wasn't much of a problem for Delle Donne, and it has been an intermittent flare-up in recent weeks.
"She's just had kind of ongoing, late in the season, just tightness," he said. "And we've been able to treat it, and it's responded pretty well, and she's been OK.
"I don't even know what to tell you about it right now, other than it is an injury, and we're going to figure it out."
The Sun outscored the Mystics 23-10 after Delle Donne left and led 29-17 after one quarter. The Mystics were able to tie the score at 76 in the fourth quarter, but Connecticut pulled away.
"I mean, just we've got to stay true to who we are," Washington guard Kristi Toliver said. "We will regroup. We will bounce back. This team is not in any type of panic mode at all."
Delle Donne missed three games during the regular season because of lingering knee soreness in May and a broken nose in July. She has continued to wear a mask to protect her nose. Other than that, she has been relatively healthy all season.
Tuesday's game marked just the second time this season that she went scoreless. The other was when she played just one minute in the game in which her nose was broken.
Last year, Delle Donne suffered a bone bruise in the semifinals. She was able to play in the WNBA Finals but was limited in movement, and Seattle won in a sweep.
Delle Donne also dealt with back issues that restricted her movement in the 2014 WNBA Finals, when she was with Chicago.