On Jan. 14, Robert Murray of Baseball Essential, Stewart's new pact with the Pirates is for two years with a third-year team option.
The Pirates acquired Stewart in December 2013 from the New York Yankees. He's served as a backup for the Pirates, first to Russell Martin in 2014 and to Francisco Cervelli last year, and he has posted solid numbers across the board.
While not a power hitter, Stewart's slash line of .292/.340/.336 in two years with Pittsburgh ranks among the best in baseball for catchers. Only San Francisco's Buster Posey and Cervelli have higher batting averages, and his on-base percentage ranks ninth among players at the position since the start of 2014 (minimum 300 plate appearances).
Stewart's defense has also been decent, producing 0.6 wins above replacement (WAR) in just 107 games, per Baseball-Reference.com. It's crucial for a backup catcher to provide solid defense and manage a pitching staff, and Stewart fits the bill.
Pirates ace Gerrit Cole seemed to develop a strong rapport with Stewart last season, as ESPN Stats & Info noted prior to a September game against the St. Louis Cardinals:
Stewart can be thought of as a bonus to the Pirates' roster. He is one of the most underrated weapons on a team that is still loaded with talent despite losing Pedro Alvarez (free agent), A.J. Burnett (retired) and Neil Walker (traded to the New York Mets) from last year's playoff group.
If Stewart's ability to call a game is what it takes for Cole to pitch like the No. 1 starter he turned into last season, the Pirates will be happy with whatever he gives them over the next two years.