Welcome to the 2017 edition of Ranking the Rockies, where we take a look back at the in-season contributions of every player to don the purple this past season. The goal wasn’t and isn’t to quibble with order. Instead, it’s to get a snapshot of a player along with a look forward. For that reason, we simply sorted by Baseball-Reference’s Wins Above Replacement (rWAR) and will start at the bottom and end up at the top.
No. 25, Zac Rosscup (0.0 rWAR)
On June 26th, the Rockies shocked the baseball world, positioning themselves for a playoff run with a high-impact relief arm: left-handed reliever Zac Rosscup. Rosscup, who had been designated for assignment by the Chicago Cubs five days prior, was traded for right-hander Matt Carasiti, who had put together a solid year of his own in Albuquerque (12.76 K/9, 3.86 BB/9, 2.37 ERA).
Rosscup, like Carasiti, had a strong minor league resume, posting a 12.7 K/9, 2.6 BB/9, 2.60 ERA line in Triple-A before the trade. Rosscup has always been a strikeout pitcher—he hasn’t had a K/9 under 9 since 2010, at any level—but he struggled with his command in three previous seasons with the Cubs. The Rockies were undoubtedly attracted to Rosscup for his potential as a left-handed specialist: when effective, Rosscup’s slider is devastating on left-handed hitters, and he came to the Rockies having held left-handed batters to a .162/.303/.284 slash line in Chicago.
For the Rockies, Rosscup was exactly who we thought he was—even if he was barely used. Against lefties, he didn’t allow a hit, walk, or baserunner, and struck out over half the batters he faced (13.5 K/9, 0.0 BB/9, 0.16 FIP). Against righties, however, Rosscup struggled, allowing a .529 average and giving up two homers in a little over two innings (7.71 K/9, 0.0 BB/9, 12.59 FIP). Rosscup’s final line this season was decidedly mediocre: a 5.14 ERA and 1.29 WHIP in just seven innings. Rosscup was never given the chance to pitch in a meaningful game, and all but one of his appearances came in low-leverage situations.
2018 Outlook
So, what do the Rockies see in Zac Rosscup? There are, in all likelihood, three possibilities. If the command problems that dogged him in Chicago make their way to Denver, we’ve probably seen Rosscup’s high-water mark. But if not, it’s not hard to see an effective LOOGY who could appear in high-leverage situations in 2018. And if Rosscup can figure out how to pitch somewhat decently against right-handed hitters—which he has done in the minors—he can become an effective weapon out of the bullpen. In other words, he’s 2014 Boone Logan at worst, and 2016 Boone Logan at best, except at league minimum cost.
After the trade, Carasiti’s command got worse (4.66 BB/9 in Triple-A) and Zac Rosscup’s got better (0 BB/9 in MLB; 2.84 BB/9 in Triple-A). There may be few sentences less inspiring than “The Rockies Won the Zac Rosscup Trade,” but moves like these are vastly underrated. Given the high price and volatility of relief pitching, the non-zero chance that Zac Rosscup turns into an effective relief pitcher should be seen as a win for the Rockies. After all, the last left-handed castoff the Rockies took from the Cubs turned out pretty well. This one might too.
