Posey -- who was NL Rookie of the Year in 2010 when the Giants won the World Series -- missed most of the 2011 season after breaking a leg and tearing ankle ligaments in a collision at home plate. He opened the 2012 season in a limited role for the Giants but finished the season with a league-leading .336 batting average to go with 24 home runs and 103 RBI, helping the Giants win the Western Division and advance to the NL Championship Series.
The Giants trailed the St. Louis Cardinals 3-games-to-1 Friday, following Thursday's 8-3 loss in Game 4. Game 5 is set for Friday in St. Louis.
Atlanta Braves pitcher Kris Medlen received two first-place votes and finished a distant second to Posey. Washington Nationals first baseman Adam LaRoche received one first-place vote and finished third.
Pitchers Adam Wainwright of St. Louis, A.J. Burnett of Pittsburgh, Johan Santana of the New York Mets, Ronald Belisario of the Los Angeles Dodgers and Ryan Ludwisj of the Cincinnati Reds also received votes.