PHOENIX -- Justin Huber arrived at the ballpark early Sunday to study footage of Arizona's Randy Johnson, but the Padres' rookie outfielder didn't get too analytical.

That laid-back approach combined with looking primarily for the Big Unit's fastball paid big dividends in the top of sixth inning when Huber ripped a 1-2 fastball into the left-field seats for his first career home run.

The 392-foot blast off the future Hall of Famer gave the Padres a much-needed boost and provided the Australian with his first big moment in the major leagues.

"It was a really cool experience," said Huber, 25, who is in the big leagues for the fifth time since making his debut with the Kansas City Royals on June 21, 2005. "It's been frustrating being up in the big leagues the last few times and not getting it done. But I feel like I have the monkey off my back now. … It's pretty special, but I don't really see myself talking about it in 10 years, 20 years. Nobody in Australia really knows who Randy Johnson is. They'll be like 'Hey, good one.' I'll just enjoy the moment while it lasts."

Huber went 2-for-5 in his first start of the season. The three RBIs were a single-game career-high, which isn't surprising since Huber entered with only seven career RBIs in 105 at-bats.

"I didn't really want to mess with the slider too much," Huber said. "It turned out all right in the end. … I wasn't trying to overthink it. With limited at-bats you don't want the ones you do get to be super stressed out."

Clark improves

The Padres believe Tony Clark's injury is a groin strain and that he will likely avoid the disabled list. The switch-hitter, who injured himself during Thursday's 22-inning game, wasn't available Saturday and was only to be used in a pinch-hitting role Sunday, though he declared himself ready prior to the first pitch.

"I'm available, but I won't be stealing any bases," said Clark, who is more affected by the injury when he hits from the right side of the plate. "Coming out of that 22-inning game, my body was sore in places it hadn't been sore in before. I know how to prepare for a start … but the toll of 22, no matter how much I worked out, I just wasn't quite prepared for it. It took a little more toll than I thought."

Hensley to start rehab

Clay Hensley threw 11 pitches in an extended spring training game Friday and is headed for a rehabilitation assignment with Single-A Lake Elsinore. The right-hander, who is recovering from shoulder surgery, is expected to pitch for the Storm on Tuesday. Manager Bud Black said Hensley, who was 2-3 with a 6.84 ERA in 13 games last season, will work as a relief pitcher when he returns to the Padres.

Hensley is 1-2 with a 2.85 ERA in 35 career relief appearances.

Short hops

Manager Bud Black called RHP Mark Prior's layoff a small step back. The right-hander has been shut down for a week, but is scheduled to resume playing catch today. If healthy, Prior would go through two batting practice sessions and a side session before pitching in a simulated game. … Black said OF Brian Giles is healthy and was given Sunday off because "it's a long season." He failed to mention that Giles is only 3-for-30 lifetime against Randy Johnson. … Arizona 1B Conor Jackson had three hits against LHP Randy Wolf Sunday and went 8-for-14 with four RBIs and six runs scored in the series. That prompted Wolf to say he would take a new approach in his next matchup with Jackson. "On Friday I'm going to throw Conor underhand because everything else he hits," Wolf said. … Diamondbacks OF Eric Byrnes snapped a 14-game hitting streak by going 0-for-4.