After missing most of 2012 and all of 2013, Cory Luebke is perhaps further than ever from a return to the mound.

The Padres' talented left-hander will need a second reconstructive surgery on his throwing elbow after undergoing an MRI on Friday that showed a tear in the ulner collateral ligament. Luebke, 28, will miss his second consecutive season after his first Tommy John surgery on May 23, 2012.

"It's disappointing. I feel bad for him," Padres general Josh Byrnes said. "It's been a long road and we had some bumps in the fall, but he was sore two weeks ago. He came (to San Diego) last week and was still sore, so we took the MRI."

It had appeared that Luebke would begin this season in the bullpen and gradually ease his way back into rotation, a plan that may now have to wait until well into 2015. While Luebke had suffered a few setbacks in his rehabilitation -- 12 to 18 months for most Tommy John pitchers -- such halts are not atypical of the process.

In August, Luebke threw his first bullpen session since his surgery, only to be shut down in September because of pain. After being examined by orthopedic surgeon Dr. Tim Kremchek in Cincinnati, he resumed his rehabilitation and began throwing from a mound in November. By late December, the Padres felt Luebke had progressed far enough to at least be considered for Opening Day relief.

The results of Friday's scan erased that progress.

"We still have somewhat unanswered questions -- when did he tear it," Byrnes said. "The rehab as a whole hasn't gone smoothly, but for better or worse, we know now that he tore his UCL."