Prospect Watch: Kila Ka’aihue

Over two months into the season, the OPS leader in the International League is Kila Ka’aihue, and it’s not particularly close. Ka’aihue’s 1.073 OPS is 60 points better than Omaha Royals teammate Alex Gordon, and only J.P. Arencibia joins them with a OPS above 1.000.

Kila Ka’aihue is 26 years old. In over 2800 minor league plate appearances, Ka’aihue has compiled an OBP above .400 and an .880 OPS. Last season at AAA, Ka’aihue walked his way to a .392 OBP and a .825 OPS – Ka’aihue walked over 100 times in less than 600 plate appearances. He had a poor .272 BABIP, too – adjusting for luck and park, according to Minor League Splits, gives him a 2009 line of .293/.424/.474.

He’s made a huge step forward this year. The BABIP is up to a more typical AAA number of .341. He’s walking even more – Ka’aihue has walked 74 times in 307 plate appearances, a 24.1% walk rate which is easily the highest in all of professional baseball, easily eclipsing MLB leader (>100 PA) George Kottaras’s 18.6% rate. The power is up as well, as Ka’aihue has 32 XBH including 16 HRs, good for a .283 ISO.

Ka’aihue has been, simply put, the best hitter in the minor leagues in 2010. At age 26, it’s unlikely that he has much left to learn, and the Royals have been the third worst power hitting team in the league, with a .120 ISO. Ka’aihue (along with Gordon) would seem to be a perfect shot in the arm for a struggling offense.

There are two possible reasons for the Royals leaving Ka’aihue in the minors: first, they simply don’t believe that he’s good enough to hit major league pitching, or second, they don’t believe he fits in the roster as currently constructed.

Given Kila’s fantastic season to date, I find the first to be hard to believe. There was certainly an argument to leaving him in the minors to start the season – ZiPS projected a mere .319 wOBA, and CHONE projected a .333 wOBA, neither of which is good enough given Ka’aihue’s position and questionable defensive skills. However, given Kila’s massive step forward in AAA, there’s reason to believe he can put up a solid, .350+ wOBA in the Major Leagues. His updated ZiPS projection is already up 16 points since the season started.

With many of these AAA players that we rave about (Alex Gordon, Matt Murton, etc.), the damning evidence against them is typically a season or two or marginal MLB performance. That excuse simply isn’t there with Ka’aihue – he’s received a total of 28 Major League plate appearances. At 26, he should still be on the good side of his peak. Yes, there’s a possibility that he flames out in the Major Leagues, but perhaps he rakes and becomes a stalwart .380+ wOBA first baseman – even a .350 wOBA Russell Branyan type would have value.

The second reason carries a bit more weight: Billy Butler and Jose Guillen, the primary 1B and DH, have two of the three best batting lines on the team. Butler’s .376 wOBA is only second to David DeJesus, and Guillen’s .349 comes third. Ideally, the team finds a trading partner for Guillen, but that probably won’t happen given his awful contract. It’s possible that the team could bench Mitch Maier and his .312 wOBA in CF, shift DeJesus there, play Guillen in right, and let Ka’aihue DH. However, this would leave the Royals with a terrible defensive outfield with Scott Podsednik in left field.

The solution for the Royals really isn’t that simple. Guillen is playing too well to simply jettison, and Butler is one of the team’s best players. It seems that Ka’aihue will have to continue paying his dues in Omaha, even though he’s clearly among the best hitters in the league and well deserving of a legitimate shot in the Majors. Still, it’s getting late for Ka’aihue, at 26, and the Royals should do whatever they can to get him in their lineup at this point.