Justin Wilson has used his high-90s fastball and sharp breaking ball to be a top rookie in 2013. (Photo Credit: David Hague)

SAN DIEGO -- If you're trying to pinpoint why the Pirates' bullpen continues to be one of baseball's best, Justin Wilson has shown you.

As the Pittsburgh reliever who has thrown the most innings, Wilson leads all National League rookies in ERA (1.97) and batting average against (.183). But one year ago today when Wilson made his Major League debut at Petco Park, he was merely at the start of his transition from minor league starting pitcher to high-leverage MLB reliever.

"It's completely different," Wilson said. "Clearly you're gonna be more sore after your start, throwing more pitches compared to going in and throwing one or two innings out of the bullpen.....

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