Walker and others too much for Upton

Is Justin Upton really the answer for Seattle? Is the 25-year-old hitter worth a young top prospect? Steve Mitchell/US Presswire

Sources say Justin Upton rejected a trade to the Seattle Mariners -- one of four such designated teams in his contract, along with the Boston Red Sox, Toronto Blue Jays and Chicago Cubs.

As Dave Cameron pointed out on the U.S.S. Mariner blog, this doesn't necessarily mean an Upton-to-Seattle deal is dead. Agents request no-trade clauses (or partial no-trade clauses) in order to give the player more leverage. Last season, Upton's no-trade teams included the Cubs, New York Yankees, Red Sox and Cleveland Indians, so this isn't necessarily a situation where Upton just doesn't want to play in Seattle. Basically, Upton's agent did an excellent job of predicting a likely trade target in the Mariners:

So, if the Mariners want to continue pursuing Upton, they have to decide how much more they want to give up to get him. They’ve already settled on the players going to Arizona -- now the question is how much cash will change Upton’s mind. That could be in the form of a contract extension, but for a player in Upton’s situation, he might not want to sign a long term commitment before getting a chance to play in his new home, especially since he’s on track to hit free agency after his age 27 season. Instead of an extension, perhaps the Mariners' best bait is to either shorten the commitment, or to give him a player option.

Cameron is suggesting the Mariners could rewrite the deal to give Upton the option to bolt after two seasons rather than three. That dramatically changes the dynamics of Upton's value, especially since the Mariners are unlikely contenders in 2013 anyway.

Who are the players the Mariners would be giving up? Fox Sports reported the deal involved Taijuan Walker or Danny Hultzen plus Nick Franklin, Charlie Furbush and Stephen Pryor or another reliever.

Jerry Crasnick tweeted this:

Jason Churchill of Prospect Insider writes, "The information I am getting varies, so I can't divulge, and just prior to publishing this I was told the M's 'may have been getting two players back, not just Upton.'"

Churchill believes Walker -- who pitched in Double-A last season at age 19 -- had to have been part of the deal: "Walker is where I have drawn the line for months. If it were a straight-up 1-for-1, I'd consider it strongly. Walker plus others for three years of Upton? No thanks."

What makes Upton difficult to evaluate are his home/road splits. Arizona is a good place to hit, and over his career, Upton has hit .307/.389/.548 at home and .250/.325/.406 on the road. In other words, he hits like Robinson Cano at home and Coco Crisp on the road. His road slugging percentages since 2009: .521, .449, .439 and .344.

Of course, it's not as simple as saying Upton won't hit as well in a different park. Most players, given equal environments, will hit better at home. And Upton played a lot of his road games in San Francisco, San Diego and Los Angeles. Cameron also addressed Upton's home/road splits last week on FanGraphs:

Regression is just a fact of life when it comes to split data, and if you’re not heavily regressing splits, you’re probably using them incorrectly. ...

This is noise. This is why you regress, even large samples. And this is why you’re better off using something like wRC+, which takes known park factors into account, then you are using a player’s individual home/road splits. Or, better yet, use a projection system that also accounts for aging curves and park adjustments.

Whatever you do, though, don’t just look at a player’s road stats and assume that it’s a window into his real talent level, with the difference between his home and road stats being a mirage of the park he played in. That’s simply not how home/road splits work.

Since 2009, among those with at least 1,500 plate appearances, Upton ranks 46th in wRC+ -- below Torii Hunter and Ryan Howard but just ahead of Curtis Granderson and Hunter Pence. Depending on how deep your list of "elite" hitters goes, Upton is either at the bottom of the elite group or somewhere below it.

My biggest issue with Upton is that even though he just turned 25 in August, he appears to have stalled out as a hitter. As Matthew points out at Lookout Landing, Upton's profile has been pretty consistent the past years (other than a slight improvement in his strikeout rate):

But his park-adjusted isolated slugging has gone from .223 to .162 to .227 to .142 over the past four years. It's probably not a coincidence that Upton's rate of pulling fly balls mirrors the changes in slugging, going from 40 percent to 29 percent to 48 percent to 33 percent.

The 2010 and 2012 seasons are concerning, but 2009 and 2011 show that Upton can post All-Star level numbers. In Upton's case, with his stable approach, skills and young age, I can't find a reason why he will deviate from his performance when it comes to projecting his next three seasons combined.

Is that worth Walker, Franklin and a couple of good relief pitchers? It really comes down to why Jack Zduriencik gets paid the big bucks: You have to properly evaluate your own talent. Is Walker a future ace? Is Franklin the heir apparent to Brendan Ryan at shortstop or a second baseman who won't have a job with Dustin Ackley around? Is Pryor a mediocre middle guy or a future closer?

You saw the quote given to Crasnick. Churchill believes Walker + Franklin + more is too much. Would Upton even change his mind given different incentives? Why are the Diamondbacks so eager to trade a young All-Star signed to a good contract anyway?

I don't think I'd do the deal with Walker, and I usually take a "prospects are overrated" position. The Mariners need to see how the new Safeco dimensions play out. It could be that their offense will be better than they realize and that a year from now they'll be looking for help in the rotation rather than a middle-of-the-order bat.