Even one year ago, it appeared very likely that Daniel Murphy would not be a Met in 2016. The pending free agent was approaching age 30 and though his bat typically made up for his shortcomings in the field, it seemed unlikely that the Mets would give a long term contract to a player with his profile. Meanwhile, the Mets had a flashy, young second baseman named Dilson Herrera tearing it up in the minor leagues in 2014 and 2015. As recently as this past July, it seemed obvious that the heir apparent to the second base mantle in Queens would be Herrera.
Then there was all the winning the Mets did in August, September, and October. There was that World Series appearance. Suddenly, the New York Mets had legitimate expectations to win and win now in 2016. These things happen and things like this are good.
The first half of the prophecy came true: Daniel Murphy is no longer a Met, now on the Nationals. The second part saw Herrera get bumped with the acquisition of Pirates second baseman Neil Walker, likely a one year fill-in at the keystone. For the 2016 Mets, a team that needed to make sure they had consistent offense up and down the lineup to support their incredible starting rotation, the move was essentially a hedge. While Herrera still possesses immense upside at just 22, the risk of him falling flat in a season like this was too much risk for the Mets to take on, especially back in December when it appeared that Yoenis Cespedes would be playing elsewhere. With Herrera, a young prospect, the range of outcomes in 2016 is wide with potentially high upside or low downside. With Walker, a known quantity in his prime, the range of outcomes in 2016 is far more predictable because he's done it before year in and year out.
Where does this leave Herrera in 2016? For now, it likely leaves him a member of the Las Vegas 51s once more, not the worst fate for a young hitter. The second baseman certainly prospered in 81 games at the level in 2015, raking to the tune of a .327/.382/.511 line with 23 doubles, 2 triples, and 11 home runs as a 21 year old. Combined with his lightning fast bat, plate discipline, and athleticism in the field and on the bases, Herrera's still as great a prospect as he was a year ago even if he's not "technically" a prospect under MLB's wonky rules. And those 169 plate appearances in the majors in 2014 and 2015 aren't worth a whole lot, unless you're unfamiliar with the Small Sample Size song. At some point this season, there will be an injury and Herrera will get another chance to show his skills.
In 2015, Dilson Herrera was considered the Mets' second baseman of the future and heading into 2016, he still is the Mets' second baseman of the future. The future for Herrera just has been pushed back a year in Queens thanks to all of that winning.