Johnson then developed tightness with the nerves in his neck, a problem that was only recently alleviated.
On Wednesday, Johnson resumed playing catch. On Sunday, he played long toss for the first of three consecutive such sessions, covering 120 feet.
"It definitely feels like it's moving in the right direction," Johnson said. "It's been a frustrating."
But if there's anything Johnson has learned while recovering from his surgery last April -- and even his first Tommy John surgery in 2007 -- it's the importance of patience.
"I know never to get too high or too low," he said.
There's no timetable, manager Bud Black said, for Johnson to do anything other than play catch at this point.
Johnson, who had surgery on April 24 of last season, worked through his rehabilitation and throwing program without so much as a hiccup until he was sidelined with the triceps and neck tightness.
Corey Brock is a reporter for MLB.com. Keep track of @FollowThePadres on Twitter and listen to his podcast. This story was not subject to the approval of Major League Baseball or its clubs.