An MRI exam taken last week showed inflammation but no structural damage. He'll have another MRI on Tuesday, then see orthopedist Dr. James Andrews on Thursday for a second opinion.
Hanrahan was examined Thursday as Pittsburgh's pitchers and catchers held their first workout. General manager Neal Huntington said he expects Hanrahan to begin the season on the disabled list and isn't sure when he'll pitch again.
"Is it May 1? Is it June 1? We'll know more as we get more information," Huntington said. "We're not talking about a chronic thing. He had a little bit of soreness that went away and then came back in January."
Hanrahan first was bothered by the pain in his elbow and tightness in his forearm last August but pitched through it. It flared up again in mid-January during the team's minicamp.
"I felt good coming into minicamp, but probably cranked it up a little too much," he said.
The 28-year-old Hanrahan was acquired last June as part of the trade with Washington. The change worked well for Hanrahan, who had a 7.71 ERA in 34 relief outings with the Nationals and a 1.72 ERA in 33 appearances for the Pirates.
Although Hanrahan worked mostly as a closer for the Nationals, he was set for a middle-relief role with the Pirates.
Pirates manager John Russell had planned to use Hanrahan and right-hander Evan Meek in seventh-inning situations. Brendan Donnelly, another free-agent pickup this winter, will be Dotel's primary setup man.
"Somebody will have to step up," Huntington said. "We've got some guys who've done that before and some other guys who've got the stuff to do that job now."
Huntington said the Pirates will consider breaking camp with just six relief pitchers. The team has three days off in the first three weeks of the season, meaning a fifth starter could be freed up to do long relief.
Also Thursday, the Pirates revealed infielder Ramon Vazquez had arthroscopic surgery in November to repair cartilage damage in his right knee. Vazquez's workouts will be limited at the start of spring training, but he likely will be ready by Opening Day.
Vazquez said he hurt himself Aug. 9 while running to first base in a game against St. Louis.