Sharapova will have an MRI scan on the injury on Thursday which will determine whether she can compete in Beijing.
The third-seeded Russian beat Poland's Domachowska 7-5 5-7 6-2 but was checked over by the trainer in the second set after complaining of a shoulder problem which probably contributed to her 17 double faults. "It's obviously unfortunate," Sharapova said. "You try to do every little possible thing you can. But at the end of the day when you go on court and you're thinking about aggravating things, you're thinking about an injury, it's not really the way to play.
"It's tough to go on court and not be close to even 50%.
"I'm too good of a player to go out there and try to fight through something that can eventually become something serious."