DENVER -- Right-handed pitching prospect Daniel Winkler will soon have Tommy John surgery, the Rockies have acknowledged.
Winkler left his most recent start after 3 2/3 innings at Double-A Tulsa, where he was 5-2 with a 1.41 ERA and on the big league radar, and underwent an MRI.
A 20th-round pick out of Central Florida in the 2011 First-Year Player Draft, Winkler led the Minors last season in strikeouts, with 175. This season he and another late pick, righty Christian Bergman (24th, 2010, out of Cal Irvine) made major strides. Bergman made his Major League debut on Monday and held the Braves to two runs in six innings.
Thomas Harding is a reporter for MLB.com. Read his blog, Hardball in the Rockies, and follow him on Twitter @harding_at_mlb. Cody Ulm is an associate reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.