NEW YORK (AP) -- San Francisco Giants catcher Eliezer Alfonzo has been suspended 50 games for testing positive for a performance-enhancing substance. He's the first player penalized this year under Major League Baseball's drug program.

The 29-year-old Venezuelan was optioned to Triple-A Fresno just before opening day and is batting .306 with three homers and 14 RBIs in 16 games. The suspension will start tomorrow.

Alfonzo played 113 games with the Giants in the 2006 and 2007 seasons, batting .263 with 13 homers and 45 RBIs.

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