The Sky (14-10), who are facing the Sparks (15-9) for the second time in five days after suffering an 84-81 loss in Los Angeles on Sunday, saw Jantel Lavender suffer a fractured left foot in their 87-84 victory at Las Vegas last Friday. She underwent season-ending surgery Tuesday.
Lavender averaged 10 points and a team-high 6.9 rebounds while starting all but one of Chicago's first 23 games. Astou Ndour will likely take her place in the starting lineup since Cheyenne Parker has been effective coming off the bench with averages of 7.8 points and 5.4 rebounds.
"Jantel's leadership and spirit will stay with us as she gets through this injury and as we get through it as a team," Sky coach James Wade said in a statement released by the team. "We are sad, but it gives her teammates the opportunity to step up in her absence. We will get through it."
Sky point guard Courtney Vandersloot, the league leader 8.8 assists per game, is expected to play after missing Sunday's loss due to illness.
Chicago is in the third game of four against Los Angeles and Las Vegas, with the three teams vying for two spots that offer a bye into the second round of the playoffs. The Sky carry a four-game home winning streak into this contest and have won seven of their last nine overall.
Los Angeles is looking to salvage a split of its two-game road swing following a surprising 84-78 loss at Dallas on Wednesday night that ended a season-high five-game winning streak. Chelsea Gray scored 22 points and Nneka Ogwumike added 21, but no one could stop Wings rookie Arike Ogunbowale, who had a season-high 35 points.
"We've got to start better. I think us starters have to figure out," Candace Parker told The Orange County Register after being held to four points on 2-of-8 shooting. "Even our game against Chicago where we won, we didn't start well. And I think when we get down 10, 12 in the first quarter, no matter if you are able to come back and take the lead, it's an uphill battle."
It is uncertain if Sparks coach Derek Fisher will face any league discipline following his ejection in the final minute of Wednesday's loss. Fisher stormed onto the court in protest for no foul being called after Ogwumike got knocked to the court after setting a screen.
Parker scored only eight points in Sunday's win, but it was Gray who capped a rally from a 16-point first-half deficit as she scored seven of her 26 points in the final 1:25. Ogwumike added 17 and 12 rebounds and has averaged 19.7 points and 10.0 boards while posting four double-doubles in her last seven games.