Is Michael Pineda the Yankees' ace?

Masahiro Tanaka's spring ended without much fanfare yesterday, as he allowed three runs and seven hits in 4 1/3 innings of work to the Rays, striking out just one in his final tune-up before his Opening Day start at Yankee Stadium Monday. Tanaka's fastball sat in the upper eighties as it has for most of the spring and that's become something of a concern for a guy who averaged 91.2 mph before a partially torn UCL claimed his summer last year. Spring training numbers mean nothing, of course, and Tanaka, even at 26, is a wily craftsman who may simply be holding back for the real show. Still as the Yankee Universe holds its collective breath each time his right elbow rears back to deliver a pitch - as the words "Tommy John Surgery" seem to hang over him like an eerily shaded comic book thought bubble - it's good to know that there's more to be excited about in 2015's boom-or-bust rotation.

Michael Pineda figures to slot in just behind Tanaka in the Yankee pitching order. Despite the vast difference in their professional game experience, Pineda is just three months younger than Tanaka. He's had a phenomenal spring so far, as he gets his final exhibition work against the Pirates today. In four starts, Pineda's allowed eleven baserunners in 13 2/3 innings, while striking out 17, and he has a tidy 1.32 ERA to match. For the first time in what feels like forever, Pineda isn't rehabbing from anything this year - not the torn labrum that kept him out of the majors for all of 2012 and 2013, or the strained back muscle that cost him three months last year. Instead of fighting to save his career, Pineda's now simply preparing to be a regular and dependable fifth of a rotation, something that hasn't happened for him since he was a Mariner in 2011. If he can do that for the Yankees, it's no reach for them to expect big things.

When Pineda's been healthy enough to pitch, he's never not pitched well. After signing with Seattle as a sixteen-year-old international free agent in 2005, Pineda amassed a career minor league ERA of 2.54 and a WHIP of 1.09, which included an 11.0 K-rate in 2010 in the notoriously hitter-friendly Pacific Coast League. Pineda's 3.42 FIP in 28 MLB starts in 2011 earned him a fifth place Rookie of the Year finish, and once he finally got the whole shoulder thing behind him, he came back with a vengeance, amassing a 1.89 ERA, 0.83 WHIP and a 2.71 FIP, along with an 8.43 K:BB rate across 76.1 innings last year. In 2014, he allowed two earned runs or less in 12 of his 13 starts and completed at least six innings in ten of them, while walking just seven, a rate of 0.8 per nine innings.

The great news for the Yankees is that there's room for Pineda to improve even beyond what he did last year. His average fastball velocity in 2014 was 92.5 mph, which was more than sufficient especially alongside the dominant control he featured. But in 2011, his last full season, Pineda was one of the harder throwers in baseball, averaging 94.7 and the difference showed in his strikeout rate - 6.96 per nine innings in 2014, down from 9.11 in 2011. Now a year farther removed from shoulder surgery, Pineda's been routinely sitting in the mid 90's again, which is huge for a pitcher who relies on power more than deception. A little extra zip could help bring the K-rate back up, which should help negate the effects of the regression he's likely to see from the .233 BABIP he held hitters to in 2014.

If all goes right, Brian Cashman is finally going to get a look at what he dreamed of when he dealt away prized prospect Jesus Montero amid much rabbling from his fan base. The Yankees are dealing with a lot of flaws on their roster this season, from their need for several bounce-back years in an offense that finished near the bottom of the league last year, to the uncertainty at the back end of the rotation. The drool-worthy premise of a healthy Pineda and a healthy Tanaka pitching on back-to-back days for an entire season would go a long way in masking those. The availability their top two starters, in whichever order you rank them, should be the deciding factor in whether or not they're true contenders this year.