Yankees General Manager Brian Cashman said an examination of the right-hander's throwing elbow by specialist Dr. James Andrews revealed an inflamed ligament in the same area where he had Tommy John surgery in 2004 and exploratory surgery in 2008, MLB.com reported.
Soriano, 31, has been on the disabled list six times throughout his career as a result of elbow problems.
He has been on the DL since May 17 and will need two weeks of rest followed by a rehabilitation period lasting at least 4-6 weeks before facing hitters, Cashman said.
"He's got, obviously, a real issue," he told the Web site. "It's something that we need to take care of and be careful with it, and if it's taken care of properly, then it will be behind him -- we hope -- and you move forward."
Soriano signed a three-year, $35 million contract with New York after coming off the best season of career in 2010, when he recorded 45 saves and a 3-2 record in 64 appearances for Tampa Bay.