Just when things had been going quite well for Rich Hill this season, his elbow failed him. The Red Sox lefty reliever had blown out that limb during an appearance on Wednesday, and initial reports, including one from fellow reliever Daniel Bard, had stated that he would be OK. But Hill acknowledged before Friday’s game that an MRI had revealed that the ulnar ligament in his left arm was “three-quarters of the way torn” and such an injury could potentially lead to Tommy John surgery. (Terry Francona said as much in his pregame press conference Friday.) As a result, the team placed Hill on the 15-day disabled list retroactive to Thursday and replaced him with fellow lefty Tommy Hottovy on the active roster.

Hill said he would seek a second opinion next week about potential rehab options on the ailing elbow and that he had yet to choose a specific doctor to look over the ligament.

The lefty has already battled back from an injury in his left side. In 2009 while with the Orioles, Hill underwent season-ending shoulder surgery after suffering a torn labrum.

This time around, Hill, who hadn’t allowed an earned run in nine appearances for the Red Sox in 2011, said the most difficult part to deal with won’t be the surgery or the rehab, but rather simply dealing with his lost spot on the roster.

“The frustrating part is you find a niche for yourself in the bullpen,” he said. “To have something happen that’s possibly season-ending, it’s tough to swallow. But at the same time if it is a surgical procedure that needs to happen, the success rate is there. You rehab, I’ve been through it once, and come back and be strong again.”

After being added to the disabled list, the 31-year-old lefty said he didn’t see the injury coming immediately before it hit.

“It was probably scar tissue that had broken up,” Hill said. “You kind of get that snapped feeling from the scar tissue. I didn’t feel the common symptoms of tingling down the arm or anything like that.”

Both Hill and the rest of the Red Sox medical staff won’t decide the precise course of action going forward until he has received that second opinion, but the biggest matter for the reliever is the speed and the thoroughness of the process so that he can return to the mound as quickly as he can.

“Now, whether surgery or not surgery or whatever happens, just get it done and rehab and come back,” he said.