A 2012 National League All-Star, Miley is entering his first season in the Red Sox organization after being acquired from the Arizona Diamondbacks on December 12 in exchange for right-handed pitchers Rubby De La Rosa and Allen Webster and minor league infielder Raymel Flores. Last season, the 28-year-old led Arizona and ranked among National League leaders with 183 strikeouts (12th) and 201.1 innings pitched (13th), going 8-12 with a 4.34 ERA in 33 starts. He also placed ninth among National Leaguers in ground ball/fly ball ratio (1.99), tied for 13th with 18 opponent ground into double plays, and tied for the NL lead in no-decisions (13), with 23 of his 33 starts decided by one or two runs.
The Diamondbacks' 2014 Opening Day starter, Miley went on to rank ninth among major league lefties with a career-best 8.2 strikeouts per nine innings. Among NL left-handers, only Clayton Kershaw (239), Madison Bumgarner (219), and Cole Hamels (198) totaled more strikeouts than Miley's 183. He posted a 3.17 ERA (37 ER/105.0 IP) in 17 road starts last season and owns a 3.31 ERA (124 ER/337.0 IP) in 55 career major league games away from Arizona's Chase Field, the eighth-best road ERA in the NL over the last four seasons from 2011-14.
Last year, no NL left-hander made more starts than Miley's 33. His 66 starts over the last two seasons are the most in the majors by a left-handed pitcher and trail only right-handers R.A. Dickey (68), James Shields (68), and Chris Tillman (67) overall. He is the only lefty pitcher, and one of only six major leaguers, to make at least 33 starts in both 2013 and 2014.
Following his 2012 All-Star season, he was named The Sporting News' NL Rookie of the Year, finishing second in Baseball Writers' Association of America voting to Washington's Bryce Harper. That year he tied for sixth in the NL in wins (16-11), ranked 10th in ERA (3.33), and posted the league's fifth-lowest walk rate (1.7 walks per nine innings).
A supplemental first-round selection by Arizona in the 2008 June Draft (48th overall), the native of Hammond, Louisiana is 38-35 with a 3.79 ERA and 499 strikeouts over 102 starts and four relief appearances in his four-year major league career, all with the Diamondbacks.
With this extension, the Red Sox have no remaining unsigned players eligible for salary arbitration.