It was a year ago in camp that rookie Shawn Kelley wowed the Seattle Mariners with a high octane fastball, a nasty slider – and it won him a seat in the goofiest bullpen in baseball.

Kelley’s year was marred by injury, but he returned to camp in 2010, at the suggestion of his manager and pitching coach, with an old friend from his college days.

His changeup.

“I threw it in college when I was a starting pitcher, but once I got into professional baseball as a reliever, my fastball and slider were enough, so I kind of put that pitch away,” Kelley said. “Don (Wakamatsu) asked me to work on it last winter, and I threw a lot of them.”

This spring, Kelley and pitching coach Rick Adair adjusted his delivery to make the pitch a bit tougher. Though he’d thrown it a few times in exhibition games, Saturday was its true unveiling.

“I threw two innings and only used one slider,” Kelley said today. “I faced the same (Diamondbacks) lineup on Monday and got hit. This time I showed them something different.”

The changeup had Arizona batters lunging and off-balance.

“You can throw it forever in the bullpen, but hitters tell you about a pitch,” Kelley said. “Until they swing and miss, you don’t have enough feedback.”

Two scoreless innings of results gave him all the evidence he needed. Face Kelley this season and you’ll face a fastball-slider-changep arsenal.

“It was like finding an old friend,” Kelley said.