Johnson has 29 strikes in 42 pitches

SCOTTSDALE, Ariz. -- San Francisco starter Randy Johnson spent Tuesday afternoon showing the Arizona Diamondbacks a little of what they'll be missing in 2009.

After two years of strong pitching interspersed with back surgeries and rehab, Johnson is feeling confident, healthy and quite spry for a 45-year-old. It showed in his second Cactus League start this spring, as Johnson pitched shutout ball and struck out seven Diamondbacks in three innings of work.

Johnson threw 42 pitches -- 29 strikes -- while stowing his split-finger pitch and relying exclusively on two-seam and four-seam fastballs and sliders. He dominated an Arizona lineup that included regulars Conor Jackson, Mark Reynolds, Justin Upton, Chris Young and Stephen Drew.

"I'm getting my work in, and I'm doing it in a way that keeps me happy,'' Johnson said. "I'm not laboring out there or giving up a bunch of hits or walking people. I felt pretty good today.''

Johnson, five victories short of the 300-win club, signed a one-year, $8 million contract in December after failing to reach agreement with Arizona. The Giants expect Johnson to give a huge boost to a rotation that includes Barry Zito, Matt Cain and 2008 National League Cy Young Award winner Tim Lincecum.

Johnson had some fun against his former Arizona teammates Tuesday. He briefly considered saying something to Diamondbacks catcher Miguel Montero after fielding a comebacker in the second inning.

"I was going to say something when he ran across the field to pick up the splinters of his bat,'' Johnson said.

Johnson, a University of Southern California product, also sent a clubhouse attendant to the Arizona side before the game to deliver a message to Diamondbacks first baseman Jackson, a former Cal-Berkeley star.

"Conor owes me some money, because USC beat Cal-Berkeley in football this year,'' Johnson said. "I sent over a messenger to tell him that I wanted my money, or else he was going to have a rough at-bat.''

The good-natured threat didn't faze Jackson, who singled off a first-pitch fastball from Johnson in the first inning.

"He's by far their best hitter,'' Johnson said.

Jerry Crasnick covers baseball for ESPN.com.