The decal will feature Griner's initials along with her number, No. 42, and will appear on the home court sideline of all 12 teams.
Griner has been detained in Russia since Feb. 17, after customs officials said they found hashish oil in her luggage at an airport near Moscow.
"As we begin the 2022 season, we are keeping Brittney at the forefront of what we do through the game of basketball and in the community," WNBA commissioner Cathy Engelbert said in a statement. "We continue to work on bringing Brittney home and are appreciative of the support the community has shown BG and her family during this extraordinarily challenging time."
Griner is coming off an MVP-caliber season in which she ranked second in the WNBA in scoring, sixth in rebounds, first in blocks, first in field goals made and third in field goal percentage while leading the Mercury to the WNBA Finals, where they lost to the Chicago Sky.
Phoenix starts its season at home Friday night against the Las Vegas Aces.
The Mercury has also been granted roster and salary cap relief during Griner's absence so they can carry a replacement player. The WNBA said Griner will continue to be paid her full salary.
"In conjunction with the league, the other 11 teams, and those closest to BG, we will work to keep her top-of-mind as we tip the 2022 season," Mercury executive vice president and general manager Jim Pitman said in a statement. "While we await her return, our main concern remains for her safety and well-being."