"I am retiring," Lilly wrote. "I don't want to, but I think it is the realistic decision."
The 15-year Major League veteran recently had the nerve endings on the right side of his neck cauterized by a spine specialist. The procedure allowed Lilly to pitch in the Venezuelan Winter League, but the discomfort continued.
Lilly was limited to just five starts in 2013, while posting a 5.09 ERA over 23 innings. In total, Lilly played for six organizations -- including the Dodgers, Cubs, Yankees, Blue Jays, A's and Expos.
The 37-year-old Lilly, who was released by the Dodgers on Aug. 4, compiled a 130-113 record and 4.14 ERA in 331 career starts. He amassed 1,681 strikeouts, while walking 661 during his 1,982 2/3 innings at the big league level.
Lilly's best season came in 2007, when he went 15-8 while posting a 3.83 ERA in 34 starts for the Cubs. It was the first of what turned into back-to-back seasons with at least 200-plus innings and came immediately after he signed a lucrative free-agent contract.
The native of California was originally taken by the Dodgers in the 23rd round of the 1996 First-Year Player Draft. His original plan this offseason was to find a way back to the Majors.
Ken Gurnick is a reporter for MLB.com. Cash Kruth and Gregor Chisholm also contributed to this story. This story was not subject to the approval of Major League Baseball or its clubs.