Germany's Andrea Petkovic is out of the Hyundai Hopman Cup with a serious knee injury.
The 25-year-old will also miss next month's Australian Open in a blow to her chances of climbing back up the world rankings after a year ruined by injuries.
Petkovic broke the news on her twitter account earlier this afternoon, revealing the extent of the injury she received in a singles match against Australia's Ashleigh Barty last night at Perth Arena.
"So it's a rupture of the meniscus, back to Germany as soon as possible for an arthroscopy," Petkovic said.
"Relieved it wasn't the ACL again."
She had won the first set against Barty after countryman Tommy Haas lost to Bernard Tomic 6-7 (6) 6-3 5-7 in the men's singles.
Petkovic's withdrawal meant Australia was handed a 6-0 6-0 win in the mixed doubles, giving the eighth seeded nation a 3-0 tie win ahead of Wednesday night's clash with top-seeded Serbia.