Sanchez, who suffered a setback in his recovery from a right pectoralis strain while throwing Monday, visited Dr. James Andrews Wednesday.
"Dr. Andrews just confirmed what the diagnosis was here," Tigers manager Brad Ausmus said. "He's prescribed a treatment option and still hopeful that he can be back before the season's out."
Sanchez described the pain he felt throwing his change-up as "like when you got a needle inside you, and you try to move it -- that's the pain, like that. It really hurt. This kind of pain kill me when I feel it."
Sanchez did say he felt much better Tuesday.
Ausmus declined to say what the treatment plan for Sanchez was, but did say that there has been absolutely no mention of surgery.
Sanchez was expected to return to Detroit Wednesday night.