Taillon experienced lower abdominal discomfort after his last outing in extended spring training, the club announced when he was scratched from his scheduled start June 23. He was then evaluated by the team and sent for a second opinion.
Dr. George Eid of the Allegheny Health Network will perform the surgery. A typical return to competition after the operation, according to the Pirates, is approximately two months.
That timeline would have Taillon returning to the mound in early September, meaning it's all but impossible Taillon will pitch in the Minors this year. He could pitch in instructional league play or in an offseason league.
Taillon, MLBPipeline.com's No. 25 overall prospect, had been building up his pitch count in extended spring starts. He hasn't pitched in an official Minor League game since he went 1-3 with a 3.89 ERA in six starts for Triple-A Indianapolis in 2013.
The 23-year-old right-hander, the second overall pick in the 2010 Draft, has gone 16-21 with a 3.72 ERA over parts of three seasons in the Pirates organization.
Around the horn
• The Pirates have made a few moves on the international market, reportedly agreeing to three six-figure deals. Pittsburgh's bonus pool this year is $2,111,900.
The Bucs have agreed to terms with Dominican outfielder Kevin Sanchez for $450,000 and Bahamian outfielder Larry Alcime Jr. for $350,000, according to MLB.com's Jesse Sanchez. Pittsburgh also agreed to terms with catcher Samuel Inoa for $240,000, according to the Dominican Prospect League. The Pirates haven't commented on or confirmed the reported agreements.
• Catcher Elias Diaz, second baseman Alen Hanson and right-hander Blake Wood were named to the 2015 Triple-A All-Star Game. Diaz will also represent the Pirates at the SiriusXM All-Star Futures Game in Cincinnati.
• Closer Mark Melancon set a club record for saves in the month of June. Melancon finished the month 1-0 with 11 saves and didn't allow an earned run in 14 2/3 innings over 15 appearances.
Adam Berry is a reporter for MLB.com. Follow him on Twitter at @adamdberry. This story was not subject to the approval of Major League Baseball or its clubs.