Aryna Sabalenka and Ons Jabeur became the latest Wimbledon contenders to retire early from matches in the lead up to the Grand Slam tournament.

World number three Sabalenka appeared to struggle with a shoulder injury and retired while trailing 5-1 in her Berlin Open quarter-final against Anna Kalinskaya.

Two-time Wimbledon finalist Jabeur decided not to continue because of illness after dropping the first set 7-6 (11-9) to Coco Gauff.

Reigning Wimbledon champion Marketa Vondrousova and 2022 winner Elena Rybakina also retired from their matches earlier in the tournament.

The first round of the women's singles at Wimbledon starts on 1 July.

Jabeur saved eight set points against Gauff before the American top seed clinched the opener.

The Tunisian, who appeared to be having problems breathing, was seen by the doctor before deciding not to start the second set.

"It doesn't feel like a win. We had such a good first set," Gauff said in her on-court interview afterwards.

"I wish Ons the best, I think it's something that is just going to happen today and she'll be better tomorrow, so hopefully she'll be at Wimbledon."

Earlier in the week, Czech Vondrousova slipped and injured her right hip against Kalinskaya in the second round, while Rybakina withdrew from her last-eight tie against Victoria Azarenka because of illness.

Gauff will play compatriot Jessica Pegula or Katerina Siniakova of the Czech Republic in the semi-finals later on Saturday.

Pegula was leading 4-2 in the deciding set when rain suspended play on Friday.

Kalinskaya, who now has a 7-0 win record against top-10 players this season, will face former world number one Azarenka.