The Big Unit allowed three runs over six innings of work in his second rehab start for Triple-A Tucson on Thursday. Johnson, who is coming off his second back surgery in as many years, threw 85 pitches and hit 92 mph on the radar gun.
"I would think everything's a go," D-backs manager Bob Melvin said. "Based on what I heard and the results, it was encouraging going forward."
That means Johnson will take the ball at AT&T Park against the Giants. It's a park that's been friendly to pitchers in its history, but the decision to have that be Johnson's comeback game was more about how his turn lined up than about the ballpark.
"The only thing I don't like about the place is it can be a little cold," Melvin said, referring to his hope that the weather doesn't cause Johnson's back to stiffen. "It's a great place to pitch, though, no question about it."
Johnson underwent surgery to repair a reherniation in his back last August, and while his recovery has gone well, he was about two weeks behind the other pitchers when Spring Training started.
Steve Gilbert is a reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.