Carpenter pitched on Sept. 2, making his first Major League relief appearance since 2000. That game followed a three-week disabled-list stint that resulted from a muscle strain in the back of his right shoulder.
"It didn't recover the way we wanted it to," Carpenter said.
The right-hander remains essentially a day-by-day proposition for the club. He made three starts upon his return from Tommy John reconstructive elbow surgery, then was shelved with the shoulder trouble.
"We're just checking all the time," manager Tony La Russa said on Wednesday afternoon. "I don't think he's available today."
Matthew Leach is a reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.