We throw that word around a lot, even though nobody is actually untradeable. Gary Matthews Jr. and Vernon Wells have been traded in the last 15 months. Both were popularly deemed untradeable.

But not all untradeable players are so because of cumbersome contracts. Some players are untradeable because they are so good, you're simply not going to get equal value back in a trade. Of course, circumstances conspire so these players are not actually untradeable either. Once upon a time, A-Rod was a 27-year-old SS who hit 50 home runs and played gold glove defense every year. He was traded.

I bring this up because on the Mets roster, you pretty much have the two definitions of unetradeable in their purest forms: Jose Reyes and Jason Bay.

Bay is owed something like $45m over the next 2 and a half seasons, and is currently not even an average player.

Jose Reyes, on the other hand, is currently the best non-Jose Bautista in baseball, and so, probably would not be traded, since big-market teams don't trade the best human in baseball (I can only assume Bautista is some sort of alien creature or cyborg.)

Of course, both these guys could be traded. If the Angels decided to finally land that big star they've come up empty on since inking Vlad Guerrero, and offerred up Mike Trout and their best pitching prospect, the Mets might make that trade. If the Mets ate all but a few million a year owed to Jason Bay, someone might deem that a worthy risk and make that trade.

But for all intents and purposes, both these guys have played their way into being untradeable in the last couple months, though in totally opposite fashion. And it couldn't be more fitting that Reyes and Bay are polar opposites in this way. They are polar opposites in just about every way, and embody the good and bad about the current iteration of the Mets.

Reyes is young, homegrown, athletic, fast and seems invincible right now. He's exciting, stylish, joyful and playing the best baseball of his life. He's the guy you can't trade, because you build your team around him. The guy who ends up with his number on the wall. The guy who ends up owning every single record for your team (well, the ones David Wright won't own).

Bay is old, a walking reminder of the fragile, and incredibly short-lived time that an athlete excels. He's a walking, talking (well, walking) lesson in the dangers of giving big money to a player on the wrong side of thirty. He's boring, slow, and will likely stand as the greatest example of Omar Minaya's flawed regime. He's the guy you can't trade, because who would want a guy like that?

Reyes is baseball at its best. Every at-bat is an event. Every time the ball is hit near him, an opportunity arises to see something great. This is a rare, special thing, to see a player putting it all together, all at once.

Jason Bay is baseball at its worst. Every at-bat is a painful reminder of how far he's fallen. You'd feel bad for him if he wasn't getting paid so much money. This is an all-too common thing.

What Jason Bay is at this point, we can only guess. We're nearing a full season worth of games for Bay in a Mets uniform, the sum of which is basically a guy who, were he not being paid so much money, would've been shipped to AAA. But, it was less than 24 months ago, he was one of baseball's best hitters.

What Jose Reyes will be is also unclear. He is not likely to play at this level for three, four, five full years. If he does, it will be the best extended stretch of play in the last half-century for a SS besides Alex Rodriguez, and it's simply not a smart bet to assume any given player will do the type of thing that is done a few times in a century.

But for the moment, these two occupy the opposite ends of the spectrum. Reyes represents what the Mets can be: Young, exciting, a perennial contender stocked with great players. Bay represents what they've been the past few years: disappointing, overpaid, old, boring and injured. How long each wears a Mets uniform, and how they fare in that uniform will go a long way to determining which version of the Mets we see over the next few years.