When I took writing classes in school (you took writing classes in school Barndon? It doesn't show!) I was taught to always take a stance, but leave room for the readers to form their own opinions.
Ivan Nova is making it extremely difficult for me to take a stance. Nova is 6-2 with a 5.60 ERA, 1.58 WHIP, 5.00 FIP, 1.87 HR/9, and 8.33 K/9. Nova seems to have many of the same starts in which he pitches a solid game, but one pitch costs him the game.
Last season Nova was a solid piece of the rotation, but was sent down when Bartolo Colon and Phil Hughes returned to the rotation. Nova was lights out in the minors, and was even better in his return to the majors than his first time around. Last season allowed many to have high expectations for Nova, who started the season 3-0 with a 3.79 ERA.
Nova has been winning games, but he has a worse than average FIP, WHIP, BAA, and HR/9. The Dominican righty has given up at least one home run in all but one of his starts, and has given up four or more runs in six of his ten starts. Luckily enough for Nova, the Yankees have given him run support, so his win/loss record looks impressive.
That's the negative. The positive is that Nova has shown that he is a more than capable MLB starter, and his potential replacements aren't exactly more impressive. D.J. Mitchell has pitched well enough to merit a promotion, while David Phelps is still available to make a spot start or two. Ramon Ortiz has been terrific if the Yankees want to go the journeyman route, while prospect Adam Warren has just recently started figuring things out.
If the Yankees see an exact problem they want to fix, but think the fix will take a few starts to iron out, I see no problem with burning an option or two and letting Nova work on his fixes in the minors. If the Yankees do not see any specific problems, he should be able to work with Larry Rothschild to perfect his mechanics and work through his struggles.
I wouldn't exactly be excited to see Nova get demoted, but if there is a fix to be made, the minors could be the best place for it to happen. Nova definitely should not be demoted for an extended period of time, however.