Spanish world No 9 Paula Badosa announced on Friday her withdrawal from the Madrid Open due to a persistent lower back injury.
"I wanted to let you know that unfortunately I won't be able to play Mutua Madrid Open," the former world No 2 announced on social media.
"I've tried to do everything possible until the last moment because you know how excited I am to play at home, but it's being a complicated injury.
"I hope to be 100 per cent soon," Badosa added.
The 27-year-old has not taken to the court since pulling out at the round-of-16 stage of the Miami Open in March with a back problem.
Badosa was scheduled to make her return on Friday in the second round at Madrid, but compatriot Cristina Bucsa now takes her spot in the main draw to face Veronika Kudermetova of Russia.
Prior to the start of the tournament, Badosa did hint at her possible withdrawal, telling the WTA's site: "It's been a tough injury, honestly, this one because it was totally different from the last one. It was an injury that was touching the nerves, so I was constantly having pain.
"Every day I'm feeling a bit better. Hopefully I will be my 100 per cent soon. Not right now, but soon."
Badosa has regularly struggled with injury throughout her career, with a chronic lower back problem leading her to consider retirement last year.
Her withdrawal from Madrid follows that of fellow Spaniard Carlos Alcaraz, who pulled out on Thursday with a thigh issue suffered during his Barcelona Open final defeat last weekend.