Bard to the pen? Aceves to the rotation? We’ll have to wait and see about the answers to those two questions, but one question seems almost certainly answered already: Is Felix Doubront, the fifth starter? Yes.

There are a couple of factors working in Doubront’s favor this spring: One, he is out of minor league options and two, he’s had, on the surface at least, a good spring with a 2.70 ERA in 16.2 innings of work. However, that ERA is wildly misleading. One look at his peripheral numbers and you’ll find stats that paint a drastically different picture.

First off, Doubront’s AVG against is .290 and he has walked six batters in his work so far this spring. Think about that for one second. Doubront has allowed more hits than innings pitched (18 hits in 16.2 IP) and six free passes, which means that he has allowed 24 baserunners in under 17 innings, good for an ugly 1.44 WHIP. On a positive note, Doubront has managed to generate 1.7 ground balls to every fly ball allowed.

Granted, we cannot possibly judge Doubront on a spring training inning count. However, his minor league track record doesn’t exactly shout that he will become a successful starter in the big-leagues. Doubront’s minor league career K/BB rate is 2.5, which isn’t very good considering the drastic difference in competition levels between the minors and majors. As a reference point, former Red Sox farmhand Kyle Weiland’s minor league career K/BB rate was 2.5. Last season, in 70.1 innings at Pawtuckett, Doubront struck out 7.8 per nine innings pitched and walked 3.3 per nine. Weiland, in 128.1 innings, struck out 8.8 per nine and walked 3.7 per nine. Again, the numbers, by comparison, are close with the edge in strikeout potential going to Weiland.  Another area of worry is Doubront’s track record of giving up the long ball. He allowed 0.7 HR/9 in his minor league career and almost 1 HR/9 at the Triple-A level. Home runs have also been a problem in his limited major league exposure, and in a role mostly relegated to the bullpen nonetheless (1 HR/9 in the big leagues).

2012 Projection: In order to succeed in a starting role, Doubront will need to lower his walk and home run rates. If neither of those areas improve, he’ll have to rely on strikeouts, which is not an area we can project more than league average success at.

Most projections systems provided for free at FanGraphs don’t account for Doubront as a full-time starter and ZiPS is the only one to project more than 45 innings. That ZiPS projection calls for 93.2 innings of work over 32 games, 19 of which would be starts. The projected numbers are not pretty: 4.80 ERA, 6.2 K/9, 3.9 BB/9, 0.96 HR/9 and a 1.50 WHIP. Again, these projected numbers only account for 19 starts, so a projection for no time in the pen and somewhere around 30 starts might even translate to worse numbers.

Baseball Prospectus did project Doubront as a full-time starter, however, because those numbers are privileged information for BP subscribers, I cannot share them here. Let’s just say they paint a John Lackeyesque circa 2011 picture.

Not good.

Does Doubront have a good enough arsenal to pitch in the big leagues? I’d say so, but at the same time I’d say that his arsenal isn’t good enough to project that he’ll be much more than a fifth starter at his peak. The downside is that he can’t hack it as a starter and is forced to middle relief or even a LOOGY role. I guess my point is that I’m not exactly confident that Doubront will give the Sox what they need out of the fifth starter’s position. In fact, I wouldn’t be surprised if he loses his job before the all-star break.