Luebke, 28, was off to a solid start in 2012 before undergoing season-ending Tommy John surgery in May of that year. The left-hander suffered a setback while rehabbing from the injury late in 2013 but was expected to compete for a spot in the Friars' 25-man roster before the MRI revealed additional damage, per Brock.
Luebke struck out nearly 10 batters per nine innings during a breakout 2011 campaign in which he posted a 3.29 ERA in 139⅔ innings. His ERA sat at 2.61 after five starts the next season before being shut down in late-April.
The Padres owe Luebke $8.25 million over the next two seasons and have only received 31 innings from the southpaw after signing him to a four-year, $12 million deal prior to the 2012 season.