Minor League Ball Mailbag: Can Eddie Rosario of the Twins improve?

Two questions recently came in about Minnesota Twins rookie outfielder Eddie Rosario.

"I know you liked Eddie Rosario. Do you still like him after seeing him play in the majors?"---T.R., Minneapolis, Minnesota

The second question was phrased almost identically but came in over Twitter private message from a different reader. Rosario has gone past rookie limits this year but he's worth examining given that his medium and long-term value is still unclear.

First, here is the comment from the 2014 Baseball Prospect Book following his fine 2013 campaign.

Another year, another solid season from Eddie Rosario. The scouting report hasn’t changed much here: he is a line drive hitter with gap power, will knock occasional homers, makes solid contact, controls the strike zone well enough, and plays with enthusiasm and flair. He runs well but isn’t an adept stealer, one of his few weaknesses. Originally an outfielder, he moved to second base in 2012 and is still figuring out the position. Although error-prone, his tools play there and he should continue to improve his reliability with experience. The development of Brian Dozier into a workable regular buys the Twins additional time, and Rosario could always return to the outfield if needed. I still like Rosario and he remains an upper-boundary Grade B prospect. NOTE: he was suspended 50 games in late November for using a banned substance. This will put back his timetable to the majors, although we should still see him sometime in 2014.

As you know, we did NOT see him in 2014. He missed time due to the suspension and he hit quite poorly after he came back, just .237/.277/.396 in Double-A, making him an enigma entering 2015. This year's comment:

Eddie Rosario was expected to reach the major leagues sometime in 2014, but instead reached lists of disappointing prospects. The season got off on the wrong foot with a recreational drug usage suspension, and when he came back he had a weak year in his second go-around Double-A despite performing adequately at the same level in 2013. Rosario had a reputation for hard work and good makeup for most of his career, but the drug thing and rumbles about other attitude problems recently tarnished that status. All will be forgiven if he gets the bat going again, and he hit really well in the Arizona Fall League. Expect him to open 2015 in Triple-A. I still like him, but his stock is down a little, mainly due to the slippage in his plate discipline against advanced pitching. Grade B-.

Rosario opened '15 with Triple-A Rochester and was mediocre through 23 games, hitting .242/.280/.379. He got promoted to the majors anyway when the Twins needed an outfielder (he hasn't seen any infield action this year and that's just fine) and he's held his job, hitting .271/.291/.440 with 15 doubles, 10 triples, eight homers, 10 steals in 15 attempts, and an 11/96 BB/K ratio in 350 at-bats. His wRC+ is a tick under league at 98, but his outfield defense has been good and helps bring his fWAR up to 1.6.

It's not a great season by any means, but it's not bad for a 23-year-old rookie who struggled in Double-A last year.

What do we make of him now? The first time I saw Rosario play was back in the Midwest League in 2012. At the time, he was a reasonably selective hitter, not a walk machine but not a guy who would chase stuff out of the zone enough to get himself in trouble either. That is different now. His walk rate shrank in 2014 and as noted it is very low in the majors so far, hampering his OBP.

Jeff Sullivan at Fangraphs noticed Rosario's approach last month in the context of discussing a strange home run that Rosario hit, somehow driving a very high and inside pitch over the fence. He also notes that Rosario "nearly has baseball’s highest rate of swings out of the zone" this year. He is coming by the low-walks-and-one-strikeout-per-game combination quite honestly.

Here's my bullet point current opinion on Rosario:

***I think he is operating at the upper boundary of what we can expect from him without a more refined approach.

***He doesn't have to be a walk maniac but more selectivity will most likely boost his production. Ideally he could improve his OBP without losing isolated power. But can he do that?

***Perhaps. When he was in high school in Puerto Rico and when he was in the lower minors scouts compared Rosario to Bobby Abreu. Rosario was similar to a young Abreu physically, and when those comparisons were made Rosario showed a good feel for hitting and a sound eye, also like Abreu.

***Rosario has not developed along those lines as yet, growing more aggressive and less selective as he's moved up the ladder, and I doubt he will develop as much power as Abreu eventually did. But I do think it very plausible that Rosario can refine his approach and develop more selectivity with experience. He's shown that skill in the past and it is plausibly still in there somewhere.

****Overall, this is a very long-winded way to say that I still like Rosario and I think he can correct his flaws, at least enough to have a long career. What do you guys think?