It is not totally baseball-based.
The optimal Dodger outfield is becoming clearer every day. Matt Kemp in left, a platoon of Joc Pederson and Scott Van Slyke in center, and Yasiel Puig in right. I say this as someone that isn't a big Joc strapper. Pederson would likely hit something close to the .253/.337/.347 line that Gregory Polanco has in 2014. Polanco put up similar if not better1 stats in AAA this year, yet he has struggled in the bigs. However, those low expectations are similar to what Andre Ethier has done with the bat this year, Pederson is at least kind of a center fielder and it's arguable that Joc has nothing left to learn in AAA and leaving him down there is stunting his growth.
Carrying six outfielders isn't an option. Five outfielders broke Don Mattingly's brain and he's just been picking outfielders out of a hat. On top of that, players with tons of money coming to them will get every chance to show they've still got it, so Carl Crawford and Ethier will break up that optimal outfield a lot. Matt Kemp's agent, Dave Stewart, is already airing his grievances publicly about Kemp being part of a rotation and this would just make it worse. Finally, six outfielders means having one backup infielder, and with Hanley Ramirez perpetually being considered "day to day" Juan Uribe and Dee Gordon have to play every day.
There is a clear worst outfielder on the team, Carl Crawford. Sure he's a little better than his .249/.286/.364 line, but his inability to hit lefties, play a position other than left field and continuous injury issues make him a strictly inferior player to Andre Ethier.
Unfortunately, no one wants Crawford. He's currently putting up replacement level numbers, his WAR has been over one once in the last four years and he still has $62.25 million coming to him from 2015 to 2017. Even if someone was willing to pick up a little bit of the contact, they'd see that Ned needs to act soon and wait for a DFA to happen to get even more leverage.
This is now about Ned Colletti looking out for himself. The Angels are the only team in history to eat over 20 million dollars on a dead contract1, and they did it twice. Vernon Wells cost them 28 million, and Gary Matthews Jr. cost 20. I know I wouldn't want to go to my boss and explain why we're paying an unprecedented amount of money for someone to play elsewhere two years after I traded for him. It's better for Ned if Crawford stays on the roster while he prays for a miracle.
If you want to get rid of Ethier, throw his name into the preceding paragraphs and add a slight chance that someone might be crazy enough to do it.
Unless you want to do a Yasiel Puig for David Price trade, which would be so fun but is a really bad idea, Kemp is the next name that comes up. Kemp is actually movable despite the $114 million still owed to him for the same reasons that so many of us hate the idea of trading him. When Kemp is good, something that's happened as recently as mid-2012, he's an irreplaceable player. Trading him right now could be selling low on him, and it's a move that the Dodgers would regret for years.
On the other hand, there's just as much of a shot that we'll never see a Kemp that gets better than this. Kemp has always gotten by on his tremendous physical gifts and without them, it's hard to imagine him returning to greatness. The speed that let him steal 39 bases in 2011 is never coming back, but his waning power is the bigger warning sign.
There's a basic idea that if you want to be a big league hitter you have to do one of two things: not strike out, or hit home runs. Kemp has done neither of those things recently. Kemp has the 18th highest strikeout rate in baseball this year, and he's fanning at a rate that's even greater than his career norms. Meanwhile, he hits home runs only 2.2 percent of the time, ranking him in the middle of the MLB with names like Brandon Crawford, Matt Joyce, and Asdrubal Cabrera. To his credit, he's posting the best walk rate of his career, but even with that he's still only on pace to be an average hitter this year. Kemp has to keep up a .350ish BABIP maintain this level of production, and while he has done that throughout his career, he's done that with his speed and ability to make constant hard contact. If those tools aren't there, the batting average will go with it, along with any of Kemp's value.
The other issue is Kemp's defense. While the numbers showing Kemp as a sub Adam Dunn level fielder the last two years really don't pass the smell test, it's fair to say that he's been the worst outfielder on the team this year. Replacing him with Ethier absolutely does hurt the offense, but the defensive upgrade does help to soften the blow.
The case for trading Matt Kemp is "this might be the last chance we have to do it". No matter who we're talking about I'll always bet on a guy getting worse as he enters his 30s instead of getting better. If Kemp declines like most players, or even worse he suffers another major injury, his contract becomes Crawford-esque. The case against it is that it makes the team worse in the short term unless you get a surprisingly good return, and there's a non zero chance you end up truly regretting it if Kemp finds his power stroke again. This really isn't something I want to happen, but it's a scenario that many people saw coming the second the Dodgers added a fourth big money outfielder. The idea was that the Dodgers would figure things out later, and later is now.
1. Polanco sported a .424 wOBA in the international league and Pederson is at .437 in the PCL. However, wOBA is only league adjusted, not park adjusted, and Albuquerque is the most extreme hitting park in the PCL while Polanco's home in Indianapolis is league average. Polanco also had a much better strikeout rate.↩
2. As far as I know, feel free to tell me I'm wrong about this. I was, Russ Ortiz was dumped with 22 million dollars due to him. Thanks to StolenMonkey86↩