TUCSON, Ariz. — Randy Johnson got only one strikeout, gave up eight hits and allowed five earned runs over four innings in a rehab start with the minor league Tucson Sidewinders.

The 44-year-old Arizona Diamondbacks ace is trying to come back from his second back surgery in less than a year. He went on the disabled list Sunday, a move retroactive to March 22.

Johnson gave up two runs in the first inning yesterday to the Colorado Springs Sky Sox in his first rehab start. He gave up three more in the second before holding the Sox scoreless for his final two innings. He left after throwing 78 pitches, 53 for strikes and giving up two walks and wasn't happy with the outing.

"It's frustrating because I put in a lot of time and effort this whole offseason into being ready," Johnson told the Arizona Daily Star. "The biggest reward is when you can go and get the results that you want and feel confident and feel like you're making progress."

Tucson won 12-10.

Diamondbacks coach Bob Melvin said Johnson will likely make one more rehab start. He's scheduled to start Tuesday in Tucson.