Since the 2013 offseason, Purple Row has systematically ranked and reviewed each player who made it into a game for the Rockies. The rankings are based on Baseball Reference's Wins Above Replacement model. These rankings provide a rough guide. More importantly, they offer a point of departure for us to assess each player's season, which is ultimately more important than the number attached.
Wilin Rosario began the season with the Rockies, though he didn't play that much. He logged just 14 plate appearances during the Rockies first 14 games before he was optioned to Triple-A Albuquerque. After about two and a half weeks there, Rosario was back up with the big club until being sent back down near the end of July. He returned after rosters expanded in September.
Not only did Rosario split time between the Rockies and the Isotopes, his performance was also divided. For the Isotopes: .297/.329/.534, which was 26 percent better than average for the PCL. For the Rockies: .268/.295/.416, which was 27 percent worse than league average. Additionally, Rosario's calling card at the plate was his power. Just like the rest of his batting line, he had it in Triple-A, but he didn't in the majors. Rosario's Triple-A Isolated Power, which is simply his slugging percentage minus his batting average, was .236. For the Rockies, it was .147. Other players with a .147 ISO in 2015 were Jake Marisnick and Marcus Semien. Part of the reason Rosario lost some of his pop is that he's hitting fewer balls in the air and more on the ground.
The loss of power is even more troubling because Rosario has become a catcher in an emergency only. He only caught two games for the Rockies late in the season—and only after Nick Hundley and Michael McKenry were lost for the season. His catching defense wasn't a liability in 2015. As a first baseman, however, his bat turned into one.
Once a top 100 prospect—Baseball America ranked him 49 after 2010 and 87 after 2011—as well as the Rockies' "catcher of the future," Rosario is no longer a catcher and, it appears, he might not be a member of the Rockies for much longer. When it comes time for the Rockies to decide whether or not to tender contracts to arbitration eligible players, expect Rosario to be left out.