For the first time, both winners of the award that recognizes the top offensive players in each league were getting ready to play in the same World Series.
"Miguel joined historic company this year by winning the game's first Triple Crown in 45 years," Selig said. "And, Buster was a consistent force in returning to the field triumphantly this year."
Cabrera is the first player to lead baseball in batting average, home runs and RBIs since 1967 when Boston's Carl Yastrzemski pulled off the feat.
"I am very nervous right now," Cabrera said after waiting for more than 10 minutes for Selig to arrive at the pregame news conference. "But I want to thank you very much. It's an honor to be sitting here with a Hall of Famer and commissioner."
Posey hit .336 and became the first catcher in the league win the batting title since Ernie Lombardi of the Boston Braves in 1942.
"I'm humbled that Hank Aaron knows who I am," Posey said. "Growing up in Georgia, he's a legend."