Guest post number two in baby week (or possibly baby week-and-a-half or two weeks) comes from Joe Tetreault. Joe writes about the intersection of Business and Sports as Managing Editor of the Business of Sports Networks with a focus on The Biz of Baseball as well as maintaining his own blog devoted primarily to baseball at TetreaultVision.

July is the summer trading season in Major League Baseball. The winter hot stove is well-removed. The heat is amply provided by the coming dog days of August as well as the hotly contested pennant races in both leagues. And what a fine collection of races will entertain us for the duration of this season

This pre-deadline environment prompts baseball scholars to contemplate player values in a slightly different light. Offseason evaluations tend to filter into different categories. Who are the top prospects or the top arbitration eligibles or the top free agents or even the top just graduated prospects hold our collective attention. Not because they are particularly useful to the teams, but instead because they prompt discussion, perpetuate offseason interest in baseball and help us prepare for the spring's fantasy baseball drafts.

At midseason the evaluation of player value is more team-centric. With clubs eager to solidify leads or arm up for one gallant push through August and September, they fix their attention on cutting the best deal possible which demands they balance the scales between commodities with excess value in exchange for assets to fill glaring holes.

The ever enjoyable Fangraphs attempts to objectively examine player trade values this time of year in their annual top fifty countdown. Quoting Dave Cameron's introduction to the series:

Again, I want to emphasize that this is a post about trade value, not a ranking of player performance. How well they do on the field is obviously a significant factor, but teams don’t simply make deals based on how good a guy is right now. There are numerous factors, of which contract status is perhaps the most important.

1. Evan Longoria 3B Tampa Bay
2. Jason Heyward RF Atlanta
3. Stephen Strasburg SP Washington
4. Hanley Ramirez SS Florida
5. Dustin Pedroia 2B Boston

Bifurcating the list to consider instead the value of known commodities against those who still possess upside is a useful start to shedding more light on how to best evaluate players in this season of wheeling and dealing. And that is precisely where we will begin our evaluation of high value players who could and should be on the move.

The first consideration in player movement is contract. A favorable contract made Cliff Lee very valuable to all the teams who called the Mariners. But in sweetening their offer, Texas was able to get Seattle to underwrite the majority of the money owed Lee for the balance of the season. This illustrates the first rule in deal making. In case a refresher is called for, JC Bradbury provides a succinct explanation:

The moral of the story is that when you’re paying a guy close to what he’s worth, you’re not going to get back much in a trade, even if he’s quite good.

This explains why you won't find Roy Oswalt or Lance Berkman on my lists. It is also helps to explain why relievers are under-represented, though they will certainly be dealt. A reliever's performace possesses such slight value as to make internal promotion (welcome back to the majors Michael Bowden) a more cost effective means of shoring up a team's bullpen.

For established players our criteria then are as follows:

Early Arbitration or Pre-Arbitration players or signed to favorable contracts lasting at least two additional seasons on non-contending clubs. Budget conscious contenders with internal replacements - call this the Tampa Bay proviso - are also worth consideration. For unproven assets, the consideration primarily focuses on the parent club. If they are contending and the minor leaguer is blocked either above and likely to be supplanted by a superior prospect at a lower level then they are a surplus commodity worth dangling in the hopes of obtaining a piece for the stretch run. The lists will better explain what regular definitions only adequately accomplish.

Established Players On the Go

#5 Tie B.J. Upton and Hunter Pence

Upton has been whispered in rumors, whilst about Pence little has been said. Few things better illustrate the remarkable difference between the franchises. Upton may never realize his hitting talent, but he is fast and has proven a stellar defender in centerfield. He's also just 25. Pence has demonstrated the offensive acumen that his development promised, but as a corner outfielder, his ability is overshadowed by some of the better boppers available. Pence will likely stay put, as Houston fails to recognize the above rule. Oswalt and Berkman can provide little in return because their performance value is matched or exceeded by the money owed them. Upton and Pence who are in their arbitration years can be non-tendered if their performance flags mitigating risk. They are also under team control, so if they hit better they can be retained. Upton is replaced by Desmond Jennings in Tampa Bay. Pence does not have an obvious young talent to replace him, though Round Rock's Andrew Locke is having a good age 27 season and could take over until an acquired prospect is ready.

#4 Corey Hart

#3 Jayson Werth

#2 Rickie Weeks

#1 Dan Haren

Prospects Worth Dangling

#5 Peter Bourjos Angels AAA CF

Bourjos is a good, not great centerfielder whose bat should play well at the position at the big league level and whose speed helps make him a plus defender and a fairly good stolen base threat. He's got Torii Hunter blocking him with the Angels and Mike Trout already in Advanced A after his showing at the Futures Game that drew rave reviews. Bourjos has already been surpassed by the younger player and therefore is easily expendable for the Angels.

#4 Yonder Alonso Reds AAA 1B/LF

Alonso is a very good hitter who is blocked by a great hitter at first base. Cincinnati has tried converting him to left field. But they've done the same with Todd Frazier. One of them will get to play left and the other gets dealt. Until Alonso's doubles power ages, he's the likely candidate to fetch something shiny for a postseason run in Cincinnati.

#3 Wilson Ramos Twins AAA C

It's tough when you're a level below the defending AL MVP and you both play the same position. Moving Joe Mauer from catcher before it is necessary reduces his value to the Twins, which means shopping Ramos is the logical outcome. Young catchers with hitting talent are rare enough to make Ramos an extremely attractive commodity. The Twins don't have anyone in the high minors to supplant him immediately, but with Mauer, even 27 year old Jose Morales will prove an adequate backup,

#2 Mike Minor Braves AAA SP

Minor has rapidly climbed to AAA after just four starts in Single A Rome of the Sally League last year. With less than 125 innings of professional experience, Minor is somewhat unknown, but his numbers are outstanding. With prospects like Julio Teheran and Arodys Vizcaino in the system, and Tommy Hanson, Jair Jurrjens, and Kris Medlen as young starters, the Braves have a surplus of young pitchers, making Minor (a lefty) a valuable commodity.

#1 Simon Castro Padres AA SP

The Padres have excelled in 2010 thanks in part to a pitching staff that has held opponents in check. Castro is probably a year away from contributing in San Diego, which may be too late to contribute to a potential division winner. Castro's upside makes him the least likely of the list to actually get moved, especially with Wynn Pelzer struggling in AA, where Castro has excelled. With Aaron Poreda now relieving and Latos on an innings limit, the club's need to retain young starting pitching is acute. But flags fly forever and a high end bat may require that type of sacrifice. I wouldn't bet on it, but I wouldn't bet against it either.