Johnson will make his fourth start for the Padres on Tuesday since being acquired from the White Sox on June 4. The right-hander has a 9.82 ERA in his three starts with the Padres and has allowed seven home runs over 14 2/3 innings.
It is likely that Johnson will make at least two more starts before Andrew Cashner is ready to return from the disabled list, although that won't necessarily mean that Johnson will be sent down to Triple-A El Paso. In the interest of protecting young arms, Green said the Padres are entertaining the idea of a six-man rotation once Cashner returns.
"It's just a good possibility right now," Green said. "I wouldn't say that's what we're doing. I think any way we can get it to where maybe we remove an outing from Colin Rea, I think that's probably smart for us right now. I think there's a host of possibilities that we'll cross those bridges when we get there with Cash coming back."
A six-man rotation would mean that Johnson is likely to remain with the Major League club at least until Opening Day starter Tyson Ross comes back, which currently looks to be sometime in July. Even then, it's possible that the Padres could instead move Luis Perdomo back to the bullpen and keep Johnson in the six-man rotation.
This means that the Padres are at least somewhat banking on Johnson putting things together at the Major League level over the next month.
"He had an extended bullpen session yesterday with [pitching coach] Darren Balsley, not so much in a heavy-workload setting, but more in just like technique stuff," Green said. "They played with his slider a little bit, tried to get its point of break deeper, closer to the dish. Explored a little bit of what his sinker used to be. Trying to find some movement and some life to give him more opportunity to have a higher margin of error in the strike zone."
Part of the problem with sending Johnson to Triple-A is that he doesn't have much left to prove there. In 23 Triple-A appearances last season, 22 of which were starts, he posted a 2.37 ERA and had a 2.94 ERA in eight Triple-A starts this year.
However, if the need comes, the Padres won't let that stop them from moving him back to the Minors, especially since his option has already been burned for the season.
"Sometimes those moves are necessary in order to keep depth in an organization," Green said. "That's what optionable starters are for. … It's not always that you have something to prove at that level, but sometimes it's necessitated by circumstance, and we'd be forced to do that, at time."