Teheran has been working on throwing more first-pitch strikes this spring, in addition to increasing the use of his changeup in order to become less predictable, the Atlanta Journal-Constitution reports.
The changeup was Teheran's best weapon when he broke into the big leagues several years ago, but he was throwing the pitch at the second-lowest rate of his career in 2017. In addition to struggling with his changeup, Teheran's slider was less effective last season, and he leaned on his fastball at his highest clip (64.5 percent) since 2012. With an improving lineup around him, Teheran could bounce back from a disappointing campaign if he's able to regain the effectiveness of his secondary pitches.