Darwinzon Hernandez Shows Swing-And-Miss Stuff

When lefthander Darwinzon Hernandez walked more batters than he struck out as a piggyback starter in his 2014 pro debut in the Dominican Summer League, it required imagination to see a future big leaguer. No longer.

Increasingly, the 21-year-old Hernandez has established himself as a pitcher with some of the most impressive stuff in Boston’s minor league system.

Signed out of Venezuela for $25,000 in 2013, Hernandez has gone from a pitcher with no profile to one who looks like a potential late-innings arm if he can’t stick in the rotation.

At low Class A Greenville in 2017, Hernandez went 4-5, 4.01 in 23 starts while striking out 116 in 103 innings and lowering his walk rate to 4.3 per nine innings. That represented an improvement from 2016, when he walked 6.7 per nine in 2016. Yet those numbers tell only part of the story for a pitcher with excellent stuff.

For the most part in his career, Hernandez has leaned heavily on a 93-96 mph fastball that generates some of the highest swinging-strike rates in the system along with a solid curveball. Yet his low three-quarters arm slot always seemed ideally suited to a slider or cutter, and in his final start of 2017, he leaned heavily on the pitch to great effect, showing the potential for a wipeout power slider.

Hernandez has shown a starter’s raw pitch mix, with his low slot helping his mid-90s fastball play up, yet his control problems have created both high walk rates and pitch inefficiency that raise uncertainty about his future is in the rotation.

“If he makes same jump improving his command over the next 12-15 months (that he made from 2016 to 2017), then he’s a starter,” said one evaluator.

SOX YARNS

• The Red Sox extended their player development contracts with both Triple-A Pawtucket and short-season Lowell through 2020.

• Righthander Chandler Shepherd, who has worked almost exclusively out of the bullpen since being drafted in the 13th round of the 2014, worked as a starter in the Mexican Pacific League. He will be stretched out in spring training.