Johnson is scheduled to start the fifth game of the season, April 2, on the road against the Marlins.
Johnson emerged with a dominant spring and was a no-brainer to take a temporary spot in a rotation beset with injuries. The 27-year-old left-hander has rediscovered impeccable command of a low-90s fastball and advanced curveball. He'll eventually land in the bullpen when the injured starters come back, but he can get big-league hitters out and will stick around.