PITTSBURGH -- Right-hander Jameson Taillon, considered the Pirates' top pitching prospect, will have Tommy John surgery and will miss the entire season and likely part of 2015.
Dr. David Altchek will perform the surgery in New York at a date to be determined.
Taillon, 22, began feeling pain in his elbow with two weeks remaining in spring training after being assigned by the Pirates to their minor league camp. Doctors prescribed two weeks of rest, but Taillon again felt pain when he tried to resume throwing.
While Taillon does not have a fully torn ligament, Altchek felt it was compromised to the point where surgery was necessary. Taillon will be out 12 to 18 months.
"It's very unfortunate for Jameson, but he's a hard worker and he'll have a good system support both with his family and our organization," Pittsburgh general manager Neal Huntington said.
"Having the surgery is not a bulletproof solution to the problem, but it's proven that a large percentage of pitchers return from the surgery and eventually perform at their previous level."
The Pirates used the second overall pick in the 2010 draft to select Taillon from The Woodlands (Texas) High School in the Houston suburbs and gave him a $6.5 million signing bonus, which was then a franchise record.
Taillon has gone 16-21 with a 3.72 ERA in 75 games over three minor league seasons. He was scheduled to begin this season at Triple-A Indianapolis, where he went 1-3 with a 3.89 ERA in six starts at the end of last season.
Taillon was ranked earlier this offseason as baseball's No. 27 overall prospect by ESPN Insider Keith Law.
The Associated Press contributed to this report.