It's hard to think about the future at a particular position when the current incumbent, Eric Hosmer, currently has a 172 wRC+ and has been worth almost 2 wins just 35 games into the year. However, we know Hosmer won't be around forever (even if he does re-sign with the Royals) so eventually we have to start thinking about candidates to replace him after the 2017 season (which doesn't seem so far away).
I want to nominate my candidate for the possible first base hole: Ryan O'Hearn. Here's what I wrote about O'Hearn in my top 30 list, where I ranked him 13th overall:
It's hard not to immediately like a draft pick when he goes 5-5 with a home run and a stolen base in his debut. O'Hearn hit the ground running in the Pioneer League recording hits in 16 of his first 18 games and 30 of his first 34 games. His longest streak without a hit was a 3-game/15-PA run from 7/31-8/4. There were only 6 games (out of 64) that he didn't reach base via a hit or walk. Truly beat up the Pioneer League (driven by a .425 BABIP) on his way to being named the league's MVP.
Out of high school he was a 2nd team All-American (alongside Joey Gallo, Gavin Cecchini, Jose Fernandez, Robert Stephenson, and Henry Owen) that went undrafted out of Wakeland, Texas.
O'Hearn didn't get a lot of love pre-draft this year, likely given the 8 home runs he hit in a non-power conference, but Don Sanders Stadium has been described as being very pitcher friendly and a hitters graveyard. It does seem that once O'Hearn moved to a more neutral confine of Idaho Falls/Pioneer League his power shot back up. Idaho Falls deeply suppresses home runs yet O'Hearn hit 5 of his 13 there while slugging .656 (.560 away).
O'Hearn features a relax setup with his bat lurching over his shoulder like a lumberback, a setup he's carried since college. Decent bat speed and torque helped him muscle a few pulled home runs over the right field wall, but O'Hearn also goes the opposite way often.
Pre-draft he was pegged as a below average defensive first baseman. I haven't seen a lot of him defensively there and am just relying upon reports, but it's probably safe to say that he won't be a defensive asset there and his impact will be bat driven. Every time I saw him play he was playing RF (did so 15 times last year) and there isn't much speed/defense there either. Moving him to right would allow some room on his bat and I'd imagine if he were to reach the majors he'd be there in theory (especially if Hosmer is still on the team at that point).
Don't expect his Pioneer League numbers in each level obviously, but he's someone who could strut into the top-10 next year, especially if he hits well in A+. O'Hearn will be 21 next year which is well within the prospect age range of A/A+. It's a bat first profile, and if he destined for 1B then he'll need to really hit. I question if 20+ home runs could happen consistently though as you'd expect out of a 1B.
What O'Hearn has done so far this year is continue to slug the whatever out of the ball. As of this writing he is hitting .261/.333/.478 with 7 home runs on the year, good for a 131 wRC+. What's equally as nice possibly is his 10.1% walk rate and 23.3% K-rate which is more impressive given the power he's displayed. O'Hearn is currently tied for the South Atlantic League and all of A Ball lead in home runs.
With O'Hearn, it's not just pull power, but power everywhere.
He can go opposite field
And yeah, of course he can pull it too...
There's a lot of power there. Those straight away center shots would be impressive in batting practice let alone in game (which would grade out to 60 power - possibly 65). Meanwhile opposite field power is an excellent sign of current and indicative of future power output.
O'Hearn was a younger junior draftee who was just 20 years old in his professional debut and won't turn 22 until July (for instance 1st rounder Casey Gillaspie - another 2014 first baseman drafted - turned 22 last January). Ryan hit 13 home runs in 64 games last year, and has 7 so far in 31. That paces him for almost 30 home runs over a full season campaign. Something a Royals prospect hasn't done since Wil Myers hit 37 over two leagues in 2012 and Moustakas in 2010 (36 total).