Red Sox starter Rubby De La Rosa must make progress soon

Jul 29, 2014; Boston, MA, USA; Boston Red Sox starting pitcher Rubby De La Rosa (62) pitches during the first inning against the Toronto Blue Jays at Fenway Park. Mandatory Credit: Bob DeChiara-USA TODAY Sports

On the surface, Rubby De La Rosa‘s ten 2014 starts with the Red Sox have been quite impressive. He has trimmed his ERA to a tidy 3.43 and while his K/9 has slipped from 8.6 in Pawtucket to 6.0 in Boston, his BB/9 has also fallen from 3.8 to 2.8. However, while De La Rosa’s 2014 season is certainly his best showing in a Red Sox uniform, don’t yet count on him sticking as a Major League starter.

De La Rosa has a number of factors working for him; he is still just 25 years old and throws two excellent pitches– a hard fastball and soft change with great movement– with his improved command helping both pitches play up. On the other hand, though, there are also factors– one in particular– which could prevent De La Rosa from ever sticking in a Major League rotation.

See, while De La Rosa does throw two excellent pitches, those are also, for all intents and purposes, the only pitches that he throws.

A starting pitcher typically needs to throw at least three average Major League pitches and, while De La Rosa has two above average pitches, it isn’t the same as even having three average ones. Even if a third pitch isn’t of the quality of the first two, it serves as an option to keep hitters off balance. And while De La Rosa technically has a third pitch, he only throws his breaking ball 12.3% of the time this season (as opposed to 57.8% with his fastball and 29.9% with his change) and, even in its limited usage, it has not been effective as opponents have batted .318 against that breaking ball.

But, you might say, De La Rosa has been effective this season despite only regularly throwing two pitches. That’s true, but once opponents become more familiar with his limited arsenal, both through advanced scouting and over the course of a game, not only will his breaking ball become less effective but so will his fastball and change. Hitters will learn to expect one of two pitches and will be able to simply sit on one offering from De La Rosa.

Of course, since De La Rosa has one of the highest ceilings of any pitchers in the Red Sox organization, the Red Sox will likely donate plenty of time in an effort to develop a third pitch for their young fireballer. Since the rest of the season represents a trial period for several Red Sox youngsters, De La Rosa (who is one of the bigger names in that mix) can focus on improving his breaking ball and utilizing it more frequently.

After all, if De La Rosa is even able to raise that breaking ball to league average, he could become a fixture in the Red Sox rotation for years to come. Just 25 years old, he has a phenomenal fastball-change combination, averaging 93.5 mph on his fastball and 85.4 mph (with great movement) on his change; however, two great pitches are only so useful over a six or seven inning start. At 25 years old, he does have time to improve; however, if he can’t add at least an average breaking ball in the next year or so then he may never live up to his true potential. And while a dominant late-inning reliever is valuable, it doesn’t compare to even a mid-rotation starter. However, the Red Sox will have to determine which of those roles Rubby De La Rosa will occupy for the future and that decision may have to come relatively soon.