Whiteside played in 187 games for San Francisco from 2009-11 before spending most of this past season with Triple-A Fresno, where he posted a .224/.296/.303 batting line. Whiteside will bolster the Yankees' catching depth, which includes former Giants catcher Chris Stewart, who was dealt to New York for reliever George Kontos in a Spring Training trade this year.
The 33-year-old Whiteside went 1-for-11 in only 12 Major League games this season, but he's better known for his defense, as was Stewart when the Yankees acquired him.
Setting up behind the plate for the Giants' loaded pitching staff, Whiteside has recorded a 3.32 catcher's ERA since 2009, the lowest such mark among all Major League backstops during that span.
The Giants used Whiteside as their starting catcher following Buster Posey's season-ending injury in 2011, only to have Stewart take over that role later in the season. Whiteside was behind the plate for one of the Giants' finer moments in San Francisco -- prior to their two World Series championships, of course -- as he caught Jonathan Sanchez's no-hitter against the Padres in July 2009.
After trading away Stewart this spring, the Giants gave the backup catcher job to the switch-hitting Hector Sanchez, who offered a stronger bat than Whiteside, a career .215/.273/.335 hitter with 10 home runs and 43 RBIs. Sanchez went on to bat .280 in 74 regular-season games, giving Posey time to rest or play first base.