I'm doing this partly because, while reading today's Cliff Lee rumors, MLBTR says the Mariners are seeking a stud catcher close to MLB ready.  So I thought I'd look at my database and see who qualifies.

MLB studs:

Buster Posey, Matt Wieters, Carlos Santana.  Despite not having the same level of hype, this year's pair of rookies have quickly established their bats are superior to Oriole Jesus.  It's still too early to give up on Wieter's bat though, and for a catcher he's not terrible.  Plus, he is an outstanding defender.  None of these guys are going anywhere.

Tier 2: Jesus Montero, Fransisco Cervelli, Hank Conger, Lou Marson, Jonathan Lucroy, Alex Avila, Tyler Flowers, Bryan Anderson, Jason Castro, Josh Thole.

Montero is the one with the highest upside, but may not stick at catcher.  Cervelli and Marson are capable big league receivers but lack power.  Lucroy and Castro look like they can field the position and have offensive potential.  The others need work with the glove but could be good hitting catchers.  Conger, at 22, is younger than this group other than Montero.  He's already in AAA, walks as often as he strikes out, and has shown power potential in the past.  He hasn't hit the ball very hard this year though, and still has a lot of work to do on defense.

Tier 3: Jarrod Saltalamacchia, Jesus Flores, Josh Donaldson, Wilson Ramos, Austin Romine, JP Arencibia. 

Salty has to recover from Mackey Sasser disease.  Flores looked very promising but hasn't played this year after shoulder surgery.  Arencibia has big numbers in AAA this year, but is doing it in an extreme hitter's park.  CHONE is not convinced he's for real.

Which players could be offered in a trade?  Depends a lot on where his team ranks in the standings. I'd say:

Studs: none

Tier 2: Conger, Flowers, Anderson, Thole

Tier 3: Ramos, Romine