(Photo credit: Michael Chow/The Republic / USA TODAY NETWORK)

The Phoenix Mercury will be the No. 7 seed heading into the WNBA playoffs, while the Los Angeles Sparks, with the league's worst record, are trying to end their season on a positive note when the teams play Tuesday in Los Angeles.

The Mercury improved to 18-20 after their 93-88 win on the road against the Chicago Sky on Sunday.

Phoenix is 1 1/2 games behind the Indiana Fever (20-19) for the No. 6 seed with two games remaining, while the Fever have one. Indiana owns the tiebreaker between over Phoenix with a 3-0 sweep of the season series.

Brittney Griner scored 26 points with 10 rebounds and Diana Taurasi added 25 in Phoenix's win at Chicago. Natasha Cloud had 18 points and 11 assists, while leading scorer Kahleah Copper (21.6 points) missed her second consecutive game with a back injury.

Mercury head coach Natt Tibbetts said defending Griner continues to be a chore for defenses. Griner was 12 of 20 from the floor.

"You hope that she settles (for poor shots) or hope you can get her pushed off the block early, in the possession," Tibbets said Sunday about the options for defenses guarding Griner. "But she shot a ton of paint shots and that's what we need."

Sophie Cunningham, who just signed a contract extension through next season for the Mercury, made two free throws with 5.5 seconds remaining to seal the victory. Cunningham finished with 13 points and five rebounds.

Cunningham is a candidate for the WNBA Sixth Player of the Year award averaging 8.2 points, 4.0 rebounds, 2.0 assists and 1.0 steals per game to match a career high.

The Sparks (7-31) lost their seventh straight game in a 90-87 defeat on the road against the Seattle Storm on Sunday. Dearica Hamby (17.1 points per game) had 25 points, 11 rebounds and four assists in the loss to Seattle.

Decimated by injuries, Los Angeles will miss the playoffs for the fourth straight year. The most serious injury was first-round pick Cameron Brink's ACL tear in June. Lexie Brown (Crohn's disease) and Layshia Clarendon (mental health reasons) also have been out.

"She's just been so important for us and shouldered so much early," Sparks coach Curt Miller said of Hamby. "She's the most improved player in this league."