I dug this out of the Yahoo question and answer section:
Catchers, even if they are good fielders, are used in the DH role (usually NL catchers DH during interleauge player).
Here are some of last year's numbers:
Starting Catcher, Games at C, (Total Games)
Joe Mauer -- 139 -- (146)
Russell Martin -- 149 -- (155)
Brian McCann -- 138 -- (145)
Jason Varitek -- 131 -- (131)
Kurt Suzuki -- 141 -- (148)
Nowadays, the average is probably between 120-150, around 130 mostly.
Some guys have great durability, though.
Randy Hundley caught 160 games in the 1968 season. Gary Carter caught over 135 games nine times. Remember, for last year's totals, there's 162 games in a season.
Based on these numbers we could expect Vaz to catch between 900 and 1100 innings.