The team says Foltynewicz is expected to be released from the hospital Thursday and will continue a treatment of blood thinners for at least six weeks.
Foltynewicz had the front part of his first rib removed Monday in a procedure performed at Wellstar Kennestone Hospital in Marietta, Georgia. The Braves were in New York to play the Mets.
Foltynewicz was taken to an emergency room Friday with swelling and redness in his arm, assistant general manager John Coppolella said Sunday.
Foltynewicz is 4-6 with a 5.71 ERA in 15 starts and three relief appearances. The right-hander last pitched on Aug. 25 and was placed on the 15-day disabled list Sept. 2.