Johnson, 30, has not pitched this year due to a strained flexor muscle suffered in spring training. Forearm strains are a common symptom of an elbow problem. Johnson had his first Tommy John surgery back in 2007 and he had a bone spur removed from his elbow this offseason.
In 16 starts and 81 1/3 innings for the Blue Jays last season, Johnson went 2-8 with a 6.20 ERA (66 ERA+) and 1.66 WHIP. He did manage to throw 191 1/3 innings with the Marlins in 2012 (107 ERA+), but was limited to only 60 1/3 innings in 2011.
The Padres signed Johnson to a one-year, $8 million contract this offseason. Because he will make fewer than seven starts in 2014, the team gets a $4 million club option for 2015.
Johnson joins Kris Medlen, Brandon Beachy, Jarrod Parker and teammate Cory Luebke as players who needed a second Tommy John surgery in 2014.