Trade-deadline tiers: Who could move? And what are they worth?

The potential sale of the Marlins could change what happens to Marcell Ozuna, Christian Yelich and Giancarlo Stanton. Rob Foldy/Getty Images

Last week, we slotted teams into tiers based on how likely they are to buy or sell at the looming trade deadline. Today, it's the players' turn.

There are countless variables when it comes to teams' moving players during the season. Just to list a few: Years and money left on the contracts in question. Quality of the players. Evaluation of other teams' prospects. Number of teams buying and selling in the marketplace. Soundness of the decision-making processes of the executives in discussion. Every deal is different, and so is every season's trade period.

Those factors are somewhat complicated this summer because it's the first deadline period under the new collective bargaining agreement. That deal, which changes the way teams are compensated for departing free agents, could result in more action come the end of July, as teams out of contention will look to get some return on players expected to depart after the season. Or maybe it won't work that way at all. At this point, we don't know.

With that in mind, we've attempted to slot trade candidates into four tiers. Each tier has a fairly specific definition, along with the kind of return it can be expected to bring. That return can vary wildly from player to player, so keep that in mind. By this method, if we were to throw Mike Trout in as a trade candidate, the expected return would be far more than what's listed here. But these general parameters reasonably describe how the market has behaved in recent years for in-season swaps.

Who is in this pool of players? The probable free-agents-to-be from selling teams are the easy ones, and they fall into one of two tiers reserved for rentals. Only the free agents from clear buyers have been omitted, though sometimes players meeting that description get traded, too. The players in the other tiers have been identified somewhat subjectively, based on their teams' buy or sell probabilities and the needs of various organizations to reboot. Most of these names have popped up on the rumor mill at one time or another. However, there is no way to make an exhaustive list of trade candidates. Pretty much all players, at some level, are trade candidates, so don't be surprised if and when a player not listed here ends up being dealt.

Also, we're slotting only players currently on 40-man rosters; no prospects are included in this exercise. Contract data used here and the list of potential free agents were taken from Baseball Prospectus. Some of the possible free agents have contract options that will be decided after the season (noted in parentheses), so they might not be rental players in the purest sense. Some players are currently battling injuries that might affect their trade value.

Finally, players within each tier are listed in order of their Wins Above Replacement (per Fangraphs.com) thus far in 2017, so the listed order might not reflect the actual value players have in the marketplace.