Luebke, who last pitched on April 27, will have surgery on Wednesday in Los Angeles to repair what he referred to as a significant tear in his ulnar collateral ligament.
"This is kind of what we were leaning toward all along," Luebke said on a conference call. "Hopefully, we're looking at a mid-May return [in 2013]."
The surgery will be performed by noted orthopedist Lewis Yocum.
Luebke had been deciding whether to have reconstructive elbow surgery or to try to pitch with the tear in the ligament after an extended period of rest and rehabilitation, which was eventually deemed a far riskier path to choose, with no guarantees that he wouldn't need surgery in the future.
"We looked at rehab choices, but there was no chance of me making a start until mid-August," Luebke said. "After talking to some of the doctors and people who have been through it, we knew the ligament wasn't going to heal itself.
"It was going to be a battle to pitch through, and that was something I didn't want to go through."
Luebke went on the 15-day DL on May 2, retroactive to April 28. He was 3-1 with a 2.61 ERA.
Aside from medical opinions, Luebke sought out the experiences of some of his peers who had elbow surgery, like Dodgers pitcher Chris Capuano and new teammate Eric Stults.
"I talked to some guys I played with in college," Luebke said. "I had a chance to talk to Capuano and he went through it twice. Talked to Eric Stults, he went through it in 2003. There were no regrets from any of the guys who had it done."
Luebke said the injury to his elbow wasn't incident specific, though he's certain that it occurred during a start against the Phillies on April 21 when he tossed eight scoreless innings in a game at Petco Park.
It was during his next start in San Francisco on April 27 when Luebke knew something was amiss.
"It wasn't one pitch or something I felt leading up to it. The first 4 1/2, five starts, I felt great," Luebke said. "We think it happened at some point in that Phillies game. The next day, it was sore as normal. I threw a light bullpen [session] that week and it felt a little off.
"The next start against the Giants, I could tell that something was a little off. All along, I thought it was tendinitis or a strain. When they told me [the extent of the injury], it caught me off-guard."
On Sunday, the Padres moved Luebke to the 60-day disabled list in order to create a spot on the 40-man roster for pitcher Matt Palmer, who joined the team from Triple-A Tucson.
Manager Bud Black said Sunday that Luebke was leaning in the direction of having surgery, and that he certainly had empathy for the process that has led him to this point.
"When you add it all up, everything that he's gone through the last three weeks, all the opinions, advice, thinking through it, I think this is the course of action he's going to take, getting the surgery," Black said. "[It's] very tough, a tough decision."
Luebke signed a contract extension in March that guarantees him $12 million and could earn him as much as $27.75 million and keep him with the Padres through 2017.