RIYADH, Saudi Arabia -- Jessica Pegula withdrew from her last match at the WTA Finals on Wednesday because of a left knee injury.
The American, who lost her first two matches and was already eliminated from semifinal contention at the season-ending tournament, will be replaced in the Orange Group by first alternate and ninth-ranked Daria Kasatkina.
Sixth-ranked Pegula, who was scheduled to play second-ranked Iga Swiatek on Thursday in her last round-robin match, said she decided to withdraw because she was not feeling "comfortable moving on court."
"Just been kind of struggling with a little bit of an injury, and for whatever reason, it kind of really flared up this week. Not really sure why," Pegula said. "In the few days before practice, it felt really, really good, but it started creeping up right before my first match."
Pegula lost to Coco Gauff and Barbora Krejcikova.
Swiatek still has a chance to join Gauff as the other semifinalist from the group. A win over Kasatkina combined with a win by Gauff over Krejcikova would send Swiatek into her third straight WTA Finals semifinal.
