The 29-year-old Rosscup will provide Colorado with a potential lefty specialist. Over his career, he has struggled against righties (and with his command) while dominating opposing lefties to the tune of a .162/.303/.284 slash. He has spent most of the current season at Triple-A, posting 17 strong appearances there (12.7 K/9, 2.6 BB/9, 2.60 ERA).
It’ll be interesting to see if there are any near-term roster moves from Colorado that help explain the move. The club already has two power, late-inning lefties in the pen in Jake McGee and Mike Dunn, though the latter has been hit hard. And converted starter Chris Rusin, another southpaw, continues to post excellent numbers in a relief role.
As for Carasiti, 25, he lost his MLB roster spot after making his debut last year. He hasn’t been called back to the majors in 2017, but has been awfully impressive at Triple-A. Over 30 1/3 innings, he owns a 2.37 ERA with 12.8 K/9 against 3.9 BB/9.