A breakdown of the withdrawals, retirements, and medical timeouts happening in the 11th and 12th weeks of the 2017 WTA season.
WTA Staff

Miami Open

Pre-Tournament Withdrawals

Serena Williams (left knee)

Petra Kvitova (left hand)

Timea Bacsinszky (left wrist)

Sloane Stephens (left foot)

Camila Giorgi (back injury)

CiCi Bellis (GI Illness) - withdrew before 1R vs. Tomljanovic, replaced by LL Linette

Retirements

Lesia Tsurenko (left thigh) - 1R vs. Beatriz Haddad Maia, 3-2

Danka Kovinic (low back) - 1R vs. Peng Shuai, 6-2

Zhang Shuai (GI Illness) - 1R doubles with Stosur vs. Atawo/Chan, 7-6(4), 1-2

Medical Timeouts

Christina McHale (GI Illness) - 1R, d. Annika Beck, 6-7(2), 7-5, 6-0

Katerina Siniakova (right foot blister) - 1R, l. Bethanie Mattek-Sands, 6-3, 4-6, 6-4

Sara Errani (right lower leg) - 2R, l. Zhang Shuai, 4-6, 6-4, 7-5

Bethanie Mattek-Sands (GI Illness) - 2R, d. Elina Svitolina, 7-5, 6-4

CoCo Vandeweghe (right hand laceration) - 2R, l. Jana Cepelova, 6-2, 3-6, 6-1

Julia Goerges (right foot blister) - 2R, d. Carla Suárez Navarro, 6-4, 7-6(4)

Shelby Rogers (left foot blister) - 2R, d. Daria Kasatkina 6-4, 5-7, 6-0

Aliaksandra Sasnovich (upper back) - 2R, l. Johanna Konta, 6-2, 6-7(5), 6-4

Kiki Bertens (right knee) - 2R, l. Risa Ozaki, 6-4, 4-6, 6-1 - later withdrew from doubles

Garbiñe Muguruza (right toe blister) - 2R, d. Christina McHale, 0-6, 7-6(6), 6-4

Jana Cepelova (left abdominal) - 3R, l. Barbora Strycova, 6-2, 6-4

Kirsten Flipkens (left finger laceration) - 3R, l. Dominika Cibulkova, 6-2, 6-3

Yaroslava Shvedova (right ankle)  - 2R doubles with King, d. Jurak/Rodionova, 7-5, 6-2

Madison Keys (right shoulder) - 2R, l. Lara Arruabarrena, 7-5, 7-5

Venus Williams (provision of medical supplies) - 3R, d. Patricia Maria Tig, 6-3, 6-0

Caroline Wozniacki (right ankle) - F, l. Johanna Konta, 6-4, 6-3