Aceves had to cut short a throwing session on Tuesday after only a few tosses at the club's Minor League complex in Tampa, Fla., and he returned to New York, where he was tabbed for a rehabilitation program that will not yet include throwing.
"Backs are tricky," Yankees manager Joe Girardi said. "We really don't know. The fact that he's not throwing for a while kind of clues us in [that his return] is not going to be right away."
It was not coincidental that the Yankees moved on Wednesday to sign free-agent right-hander Chad Gaudin, who had been released by the Athletics after attending Spring Training with New York this year.
Aceves told reporters recently that he has been informed that he has a bulging disc in his lower back, and Girardi confirmed that on Wednesday. Girardi's playing career ended in part because of back problems, and he said that Aceves will have to continue to stay on top of his issue.
"Once you're a back patient and you're involved in back rehab, you're always involved," Girardi said. "It's never going to be a time where you're not doing anything for it, and I can tell you that from experience."