Johnson, a former 2012 first-rounder for the Red Sox out of Florida, features a four-pitch mix with a plus feel for pitching. The big-bodied lefty has a long windup with long arm action. Johnson has been up with parent club for two spot-starts, including a recent 5-0 shutout in which he gave up five hits, no walks, and eight strikeouts in a 6-0 home win versus the Mariners on May 27. The quandary with Johnson, however, is that he has faired better in his MLB starts than he has at Pawtucket. His control in Boston in his two starts (14 innings) in 2017 was double plus (1.9 BB/9) but at the Triple-A level in 2017 the control numbers inflate to a below average 3.4 BB/9 over 44 2/3 innings, and his larger sample size of his 2016 showed a similar below-average 3.8 BB/9 across three minor league stops and 95 innings.
To be effective against high-level bats, Johnson has to really locate his entire repertoire, and his only real weapon is his average-graded curveball (73-to-77 mph) that he uses to keep hitters off his well-below-average fastball that sits 86-to-89 mph with run and tail action to both sides of the plate. While the fastball command and movement is average, he needs to be ultra-fine with his command so he can get to his curveball, which shows downer 12-to-6 break with good two-plane depth. He shows the ability to throw it for strikes with command. He can change the shape and depth of his slider, which sits 77-to-80 mph, but it comes in with slurvy action on most offerings. His fourth pitch is a fringe-average changeup that sits in the 80-to-81 mph velo range with fading action.
His MLB starts aside, his overall inconsistency as a starter is rooted in his present inability to command the fastball and locate the curveball. He’s not a player that will wow you with his stuff, but his pitchability still gives him a chance to fill the role of a Role 30, up/down starter, as he has for the Red Sox this year. If the fastball command gains more consistency to get him into his secondary stuff, he still has an outside shot to hit a ceiling of a Role 40 number five starter for a club in need.