Dr. Tarun Jolly answers the question: 'What Is A Trigger Injection?' — -- Question: What Is A Trigger Injection And When Might I Need One? Answer: A trigger point injection is an injection that ...

ST. PETERSBURG, Fla. - Trevor Cahill received a trigger-point injection for discomfort in his upper back and the right-hander will miss at least his next start, according to A’s manager Bob Melvin.