Prospect Note: Kevin Kiermaier, OF, Tampa Bay Rays

According to Fangraphs WAR, the top three rookie position players in baseball this year are Billy Hamilton of the Cincinnati Reds (3.1 WAR), Jose Abreu of the Chicago White Sox (3.0 WAR), and Kevin Kiermaier of the Tampa Bay Rays (2.5 WAR). Kiermaier's 153 wRC+ is second-only to Abreu's 157. He also ranks second in slugging and in wOBA. The traditional stats look great of course at .297/.331/.574 with eight homers in 158 plate appearances. Add in his stellar outfield defense and you have a tremendous campaign.

Raise your hand if, pre-season, you projected Kevin Keirmaier to be the third-best rookie in baseball at the All Star Break.

I don't see any hands there. So who is this guy?

He was drafted in the 31st round in 2010 from Parkland Junior College in Illinois. He had a good debut after signing, hitting .303/.380/.431 with 17 steals in the Appalachian League, but he was unable to replicate this in the Midwest League in '11 with an unimpressive .241/.316/.338 (wRC+ 90) season. He quickly developed a reputation as an excellent defensive outfielder, but there was nothing in either the scouting reports or the stats to indicate blossoming offense on the horizon at that point.

He played 57 games for High-A Charlotte in 2012 and hit .260/.361/.367, which doesn't look that hot but was actually good for the Florida State League context as shown by a 112 wRC+. That was a hint of potential. He took a huge step forward in 2013 by hitting .307/.370/.434 in 97 games for Double-A Montgomery (134 wRC+), .263/.338/.423 in 39 games for Triple-A Durham (112 wRC+), and capping the season with one game in the majors as a defensive substitute. As noted he's been excellent this year, ripping the ball in Triple-A (.305/.362/.461) and in the majors.

Born April 22, 1990, he is listed at 6-0, 200. His overall athleticism has always been respected and scouts have been praising his glove for three years, but he looked like a fourth outfielder to me heading into the season, not a guy who could do this.

However, if you look at his record, there are markers of potential: the strong performance in the Appy League, and the fact that his production has been above-average (despite superficially not looking that great) at every stop except the Midwest League.

I did pick up on that pre-season and wrote this in my book:

He’s not a bad hitter; he has a nice swing, adequate plate discipline and some gap power, but he’s never stood out as an offensive player. He doesn’t steal lots of bases, draw lots of walks, or produce many homers. If you put him in the lineup he’d hit something like .250/.320/.370, which isn’t enough for most teams even with the defense. He’d be a very valuable fourth outfielder though, coming in frequently for late-inning defense and seeing occasional platoon action. It is also possible you could see an offensive spike from him in his late 20s, a season or two when the hits fall and he runs up a .300/.370/.430 line before settling back to his career norms. Grade C+.

The thing is, he's 24, not in his late 20s, so this offensive surge is happening sooner than anticipated. It is also taking a different form than expected, with more SLG and less OBP.

Does he maintain it? Well, his 7/30 BB/K ratio isn't very attractive and he's seen his production decline in July, .229/.229/.457 this month. Perhaps the pitchers are catching up. I am very interested in any observations from those who have seen him play frequently. What are your impressions of him? Does he settle into being a fourth outfielder or could he make it as a regular?