Ons Jabeur and Karolina Pliskova out of Madrid Open

The Madrid Open will go ahead without WTA stars Ons Jabeur and Karolina Pliskova, who have withdrawn due to injury.

On Monday, defending Madrid Open champion Jabeur took to Twitter to reveal her calf injury.

"Further to many medical examinations done, it shows that I have a small tear in my calf and I will need more time to recover," read the world number four's post in part.

This follows Jabeur's withdrawal from the Porsche Tennis Grand Prix semifinal on Saturday, where she retired hurt against eventual champion Iga Swiatek.

Meanwhile, former world number one Pliskova has also withdrawn from the event due to a knee injury suffered at the same event.

"So sorry I have to announce my withdrawal from @MutuaMadridOpen," the Czech star tweeted on Sunday

"During my last match in Stuttgart, I injured my knee. I will try my best to be ready for Rome."

The Madrid Open - which has also lost Novak Djokovic and Rafael Nadal in the men's draw - is a tune-up event for the second Grand Slam of the year at Roland Garros.