Sabalenka and Jabeur both retire from Berlin Open quarter-final clashes
Sabalenka was forced to retire from her quarter-final against Russia's Anna Kalinskaya due to shoulder pain when the Belarusian trailed 5-1 in the opening set.
It marked the first time in her WTA Tour career that Sabalenka had retired from a match because of injury.
Kalinskaya has reached the semi-finals with two walkovers after Wimbledon champion Vondrousova slipped and fell during their last-16 match, forcing the Czech player to retire.
Jabeur, meanwhile, was involved in a 72-minute opening set in her quarter-final with Coco Gauff which the American won 7-6(9) before the Tunisian retired because of illness.
Jabeur was seen getting her temperature checked before she retired.
"It doesn't feel like a win, especially because we had such a great first set. I wish Ons the best," Gauff said after reaching the semi-finals.
"I think it's something that's just going to happen today and she'll feel better tomorrow. I think she'll be strong at Wimbledon."
On Friday, Rybakina withdrew due to illness, sending Belarusian Victoria Azarenka through to the semi-finals. Rybakina was visibly struggling with what appeared to be abdominal pains.