If they fail to sign Zaun, who batted .287/.323/.489 for them in 99 plate appearances, they still could pursue another catcher and decline to offer Navarro or Shoppach a contract.
The Rays offered salary arbitration to Zaun, a Type B free agent, ensuring that they would receive a supplemental draft pick between the first and second rounds if he signs with another club.
The Book says the benchmarks for platoon performances are 2,000 plate appearances for a right-handed batter and 1,000 for a left-handed batter. Over the last three seasons Zaun has 674 at-bats versus righties in which he's hit .249/.339/.418 (.232/.353/.311 versus lefties). Dioner Navarro has hit .245/.301/.337 against righties in nearly 850 at-bats (.257/.300/.430 versus lefties) and Kelly Shoppach has hit .229/.319/.420 versus righties in 600+ at-bats (.297/.392/.621 against lefties). I don't need to tell you which two make the most sense for a straight up lefty/righty platoon.