The Pirates have declined to tender a contract to pitcher Jeff Karstens, Dejan Kovacevic of the Pittsburgh Tribune-Review reported Friday.

Karstens owns a 3.59 ERA and a 3.94 FIP over the past two seasons. Those numbers typically guarantee a tendered contract given the lower salaries in arbitration as compared to free agency, but the Pirates are concerned about Karstens' durability. Reports surfaced in late September that the Pirates were considering the move. From the Pittsburgh Post-Gazette:

"He's doing everything he can to get the best out of his abilities," [Pirates GM Neal] Huntington said. "Unfortunately at times, his body lets him down, and it's been various body parts."

Karstens managed just 15 starts in 2012 due to shoulder and hip injuries. In 2011, he started a career-high 26 games and pitched 162 1/3 innings. However he's 30 years old, and the Pirates apparently question his ability to make 33 starts and pitch 200 innings in a season.

The righty earned $3.1 million in his second arbitration season last year and would likely be in line for $5 million or so in salary had the Pirates tendered a contract. Although Karstens looks like a good bet to outproduce that value if healthy, Pittsburgh apparently saw the durability issues as too prominent to take the risk.

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