Manager Mike Matheny offered only that he "think[s] he's going to take another day."
A Cardinals official, when asked to comment on the delay, said that the situation would be addressed on Tuesday.
Carpenter threw off the mound most recently on Friday, saying afterward that he felt strong throughout the 40-pitch session. That session came one day after a visit to a Dallas-area specialist, who confirmed that Carpenter is dealing with thoracic outlet syndrome. That condition, which is mostly commonly found in athletes who use an overhead motion, involves weakness, numbness and tingling due to pain in the neck and shoulder.
This is the second time in the past week that Carpenter has not thrown as scheduled. He was supposed to face hitters in a batting practice session last Monday but canceled because of recurring weakness in his shoulder.
Though surgery is typically the preferred course of action for those diagnosed with thoracic outlet syndrome, Carpenter hopes to maintain enough strength in his right arm and shoulder to be able to pitch this season.