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5/3/2014 7:32 P.M. ET

Peterson adjusting to playing third base

SAN DIEGO -- When Chase Headley first strained his right calf during a Spring Training drill in February, Padres manager Bud Black approached Jace Peterson with the idea of moving from shortstop to third base in camp.

Up to that point, Peterson's experience at third base could be summed up in three words.

"Nothing at all," Peterson said Saturday.

With Headley on the disabled list for another strain of that same calf, the Padres have taken a long look at Peterson at third base. He made his sixth start there Saturday against the D-backs.

Peterson, who was promoted from Double-A San Antonio on April 25, entered the game hitting .211 in his first 19 big league at-bats.

Defensively, he's made one error in his first seven games there -- including five starts before Saturday. As you might imagine, the hot corner has taken some getting used to.

His indoctrination in Spring Training to the position proved to be a blessing, he said.

"I think it helped me tremendously to take some ground balls right away there and get some reps in practice and in games," Peterson said.

Peterson, the 58th overall selection in the 2011 Draft out of McNeese State, was a shortstop during his first three Minor League seasons. Even when he reported to San Antonio, he mostly played shortstop but played third base once.

"Probably the biggest thing is when the ball comes off the bat at a different angle. It's still the left side of the diamond, but you've got to be able to pick up the contact point out front since the ball is coming quick," Peterson said. "It's just minor things. I think the more reps I get and the more I play, the better that I will be at it."

So far, Black likes what he's seen in Peterson.

"The makeup itself … this guy is a competitor and he doesn't scare off," Black said. "He's a clear thinker. He was a college football player, too, so there's some toughness to him. I like how he goes about it. I like a lot of the intangibles."

Padres add Minor League infielder Gonzalez

SAN DIEGO -- The Padres added some infield depth to their Minor League system Saturday when they traded for Pirates infielder Benji Gonzalez.

Gonzalez, 24, will report to the team's Class A Advanced affiliate in the California League (Lake Elsinore).

Gonzalez was the Pirates' seventh-round Draft pick in 2008 out of the Puerto Rico Baseball Academy.

The Pirates will receive a player to be named later or cash considerations.

Gonzalez, who can play shortstop, second base and third base and the outfield in a pinch, hadn't played in a game this season but instead was working out at the Pirates' Spring Training facility.

Gonzalez is a switch-hitter who spent the past three seasons with the Pirates' Florida State League team in Bradenton. He's a career .240 hitter with a .315 on-base percentage. In 2013, he had a career-high 27 steals.

The Padres felt they were a little short in terms of infield depth at Lake Elsinore coming out of Spring Training and have been looking for upgrades since then.

Black concerned that struggling hitters are pressing

SAN DIEGO -- No offense to D-backs pitcher Bronson Arroyo, who held the Padres to three hits in seven scoreless innings on Friday, but manager Bud Black felt his hitters contributed to Arroyo's success more than they should have.

"As well as he pitched, I felt we helped him by swinging at some balls below the [strike] zone," Black said.

Black said he's sensed recently that his hitters are pressing, the result of a slow start, which has the team ranked last in the big leagues in runs (77 in 30 games) going into Saturday's game against the D-backs.

According to FanGraphs, the Padres ranked 13th in the big leagues in O-swing, which is the percentage of pitches they've swung out outside the strikes zone (29.7 percent). The team is 11th in baseball in terms of strikeouts (246), many of which have occurred when they've expanded the strike zone.

Black certainly can't fault his hitters for wanting to be successful, but chasing pitches outside the strike zone isn't the way to do it. It can lead to weak contact or strikeouts. Either way, it's no good.

"It goes back to swinging at strikes and taking balls," Black said.

Corey Brock is a reporter for MLB.com. Keep track of @FollowThePadres on Twitter. This story was not subject to the approval of Major League Baseball or its clubs.