The Boston Red Sox promoted right-handed pitcher William Cuevas to the major league roster yesterday. He is somewhat obscure as prospects go but he performed reasonably well as a non-roster invitee to spring training this year and he's a big leaguer now. Here's the background.
Cuevas is from Venezuela and was signed by the Red Sox as a free agent back in 2009. After two seasons in the Dominican Summer League he was brought to rookie ball in Florida in 2011 and performed well (2.79 ERA, 25/9 K/BB in 39 innings), then repeated his success in the New York-Penn League in 2012 (1.40, 72/15 K/BB in 77 innings).
2013 and 2014 were much different: he struggled making the jump to High-A, combining for a 4.92 ERA in 231 innings. He improved greatly in 2015, posting a 3.61 ERA in 136 innings between Double-A Portland and Triple-A Pawtucket, with a combined 128/55 K/BB.
Cuevas is a 6-2, 215 pound right-hander born October 14, 1990. He does not throw extremely hard, maxing out around 92 but more often working his fastball in the 86-89 range with little margin for error. He mixes in a curveball and change-up, both generally rated as fringe-average quality with the change-up the better of the two pitches. He relies heavily on command and control and took a step forward in 2015 by sharpening his ability to locate and reducing a past tendency to telegraph his pitches. Although not excessively vulnerable to home runs in the minors, he is a fly ball pitcher and will have to be sharp with his location in the majors to avoid gopheritis.
At the major league level Cuevas projects as a fifth starter, long reliever, or mop-up man. Here's some video from spring training.