It's not that hard to believe that the Royals had something in place with Manaea before the draft began. With him falling out of the first round, the Royals' decision to go under-slot with the #8 pick so they could load up on the next few rounds (specifically Manaea and whomever they take at #46), and with their being little to no conversation regarding other teams' interest in him leading up to the Royals Comp. A pick (JJ Cooper confirmed well before the pick was made that Manaea would be available at 34). So, there you have it.
Without further adieu, from around the interblag:
When he is on, Sean Manaea has an excellent fastball, one of the best in the draft. It generally sits in the low 90s and can be thrown as high as 95, 96 MPH -- though he has shown problems keeping the velocity up late in games. From the low ¾ arm slot, the fastball has good running action, and is very fluid. In addition to the fastball, he throws a slider and a change-up. The slider is still a work in progress, but shows flashes of being a good pitch when Manaea has control of it, and it is breaking properly. The change-up is also developing but is a better overall pitch than the slider. It is thrown in the low 80s, so depending on how much velocity he has on his fastball, the speed differential is anywhere from 10 to 15 MPH.
From SB Nation's own Amazin' Avenue.
Manaea needed a strong finish to bring his stock back up after battling some hip issues and overcome the drop in his stuff over the last 10 months. It is not implausible to think of a scenario where the lefty tries to rebuild his stock as a senior, especially with Scott Boras as his representative, but considering where he has gone after threatening to be the top player in this class just 10 months ago, the odds of him turning down a million dollar contract right now and risk more diminishing returns next year are small.
From an actual columnist at Bleacher Report.
Before the season started, his mechanics were a cause for concern. Now you know why. His mechanics are very stressful on his body and the body is showing it. He gets his plant knee extended quickly and make his hip control all of his balance and absorb all of the rotational forces in his delivery. Then the elbow never has much flexion in it and kind of long arms the ball. With his elbow so extended, the moment arm of the forces are farther out and requires his rotator cuff to work harder along with the other internal rotators to work harder to turn his arm over. That is why you are seeing shoulder problems. The near straight elbow in a large part of his delivery puts extra stress on his elbow as well. Despite all of these issues, the delivery is surprisingly easy and smooth. He does it well, but it just doesn't put his body in a good position.
From SB Nation's own The Crawfish Boxes.
And here's his fluff page from Indiana State.
Video on Manaea:
Both via Bullpen Banter.
A big lefty with top-tier(ish) stuff and injury concerns.