Peterson making strong impression on Melvin

PHOENIX -- The last remaining piece of the 2009 Matt Holliday trade is making a lasting impression in camp.

Outfielder Shane Peterson, who came over from the Cardinals with the departed Clayton Mortensen and Brett Wallace in that deal, finished Tuesday batting .444 through 11 games.

Peterson has 12 hits in a team-high 27 at-bats, including a triple and a home run, and four RBIs. Surely he's making the A's offseason decision to protect him from the Rule 5 Draft and place him on the 40-man roster look like the right one.

"It's unbelievable," manager Bob Melvin said. "It seems like we're talking about him every day. It seems like he gets two good at-bats every day, and whether it's against lefties or righties, it doesn't matter. He hustles, runs hard, plays very hard."

On cue, Peterson picked up another two hits in Tuesday's 8-2 loss to the Royals, while also making his first start of the spring in left field. He had previously been used primarily in the later innings.

The 25-year-old, drafted by the Cardinals in the second round of the 2008 First-Year Player Draft, began 2012 at Double-A Midland for the second consecutive season, but finished it by hitting .389 in 38 games with Triple-A Sacramento. Overall, he finished with .326 average, nine home runs and 46 RBIs in just 86 games, after missing time at the beginning of the season with a sprained right ankle. He reached base safely via hit or walk in 78 of those games.

"We saw his numbers last year, didn't get to see him first-hand, but now we are," Melvin said, "and he's making big impressions."

Peterson can also play first base, and that added versatility could make him a prime target for a promotion this season should the A's need help at the big league level. Until then, he'll get his at-bats at Sacramento once camp concludes.

Jane Lee is a reporter for MLB.com. Read her blog, Major Lee-ague, and follow her on Twitter @JaneMLB. This story was not subject to the approval of Major League Baseball or its clubs.