The Rangers' ace will have the ligament-reconstruction surgery performed on his right elbow by Dr. James Andrews on Tuesday and likely will be sidelined until the 2016 season.
Rangers general manager Jon Daniels said Wednesday that Dr. David Altchek, the New York Mets' medical director and an expert in Tommy John surgery, recommended the procedure after examining Darvish on Tuesday.
An MRI last Friday revealed partially torn ligaments and inflammation in Darvish's right elbow. That came a day after Darvish felt tightness in his triceps while warming up for his spring training debut, and he then threw 10 of 12 pitches for strikes in his only inning before telling anyone about the discomfort.
Darvish was back in Rangers camp Wednesday, in uniform and playing catch in the outfield of one of the fields. He was throwing left-handed, something he routinely does during conditioning.
An All-Star in each of his three seasons since coming to Texas from Japan, Darvish started last season on the disabled list after experiencing neck stiffness in spring training. He missed only one start then, and was 10-7 with a 3.06 ERA in 22 starts. He made his final appearance on Aug. 9 because of elbow inflammation.
He is 39-25 in 83 starts for the Rangers, with 680 strikeouts in 545 1/3 innings. He led the majors with 277 strikeouts in 2013.
The Rangers, who were reigning American League champions, committed more than $107 million to acquire Japan's top pitcher. Darvish got a six-year contract guaranteeing him $56 million, and Texas had to pay a $51,703,411 posting fee to his former team, the Hokkaido Nippon-Ham Fighters.
Darvish has a base salary of $10 million this season and is owed $10 million for next year and $11.8 million for 2017. Assuming he misses this season, the only way 2017 could become a player option would be if he wins the 2016 AL Cy Young Award.
Information from The Associated Press was used in this report.