Well, he did not actually do that, and it is not my intent to disparage Justin Turner. He will always be a Dodger in my mind, but I think he should have just retired rather than go to Boston. Essentially by not signing JT and signing JDM instead, he made that trade. But like lots of athletes, Justin Turner did not know when to quit as he thinks he can still play.
JT is 38 and has lost a stop (or two). His once superb glove is not all that anymore. He is not the baserunner he once was, and over the past three seasons, he has demonstrated an inability to catch up to upper-90s fastballs.