"I've been trying to fiddle with a changeup my whole career I guess, and the split-changeup was something that finally fit me," said Johnson, who appeared in 44 games a season ago between Class-A Daytona and Class AA Tennessee and posted a 4.11 ERA in 70 innings. "It was something I could throw for strikes."
Throwing strikes is the biggest key for any pitcher and Johnson, 24, is no different. At Tennessee last season, he walked 20 batters in 47-plus innings. That inconsistency has been a part of Johnson's pro career since he was drafted.
"I really haven't shown what I can do any year I've been with the Cubs," Johnson admitted last season. "I just want to throw like I know I can."
The addition of a comfortable off-speed pitch has been a big help in that regard. Johnson began working the pitch into his repertoire last season and continued perfecting it in the off-season and during minor league spring training.
"I don't think it put any extra strain on my arm," said Johnson.
That's important to note because Johnson has been sidelined this month with an injury. He strained his elbow in the final week of spring training and remained in Arizona once full-season minor league rosters were announced.
Johnson's name is currently listed on the disabled list at Tennessee, and he expects to rejoin the Double-A team once he is healthy.
"The doctors checked me out and they said there doesn't look to be anything serious," said Johnson. "Hopefully I'll be out of (Arizona) by the end of the month."
All the while, Johnson is trying to build on his success late last year with Tennessee. He closed last season with a 1.88 ERA over his final nine appearances, notching 17 strikeouts in 14-plus innings and holding opposing hitters to a .180 average against.
"I did really well the last month to two months of the season, so this season I was working with (pitching coaches) Dennis Lewallyn and Rick Tronerud to get things squared away and to get on a roll before the season even started," Johnson said of his work this spring. "Last year, it took me a little bit before I got into a groove, and I was going to try to come into the season in that groove and in a rhythm."
The elbow flare-up may have put a dent in those plans, but Johnson's work has otherwise been routine.
"Same old stuff," he said. "I think everything has been the same. Like every pitcher in the league, I'm just trying to make everything a little bit more consistent."