What to expect from A's Manaea in big leagues

What to expect from A's Manaea in big leagues

The Oakland Athletics will promote No. 65 overall prospect Sean Manaea to make his Major League debut on Friday at home against the Houston Astros.

The A's No. 2 prospect and top-ranked pitching prospect is getting the call after his impressive start to the season at Triple-A Nashville, where he was 2-0 with a 1.50 ERA and a 21/4 K/BB ratio in 18 innings (three starts) for the Sounds.

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Manaea, 24, was a candidate to go No. 1 overall in the 2013 Draft before a hip injury derailed his junior season at Indiana State. He ultimately fell down the board to No. 34, where he was selected by the Royals and subsequently signed for a supplemental first-round record $3.55 million. Manaea flashed his potential the following year during his professional debut with Class A Advanced Wilmington, posting a 3.11 ERA and striking out 146 hitters in 121 2/3 innings across 25 starts.

Manaea's progress stalled in early 2015 as a result of oblique and groin injuries, the combination of which resulted in nearly a three-month stint on the disabled list. He finally made his season debut in late June and received a promotion to Double-A Northwest Arkansas a month later after series of strong outings for Wilmington. The A's took notice of the southpaw's success and made him their key acquisition in the deal that sent Ben Zobrist to Kansas City in the days leading up to the July 31 non-waiver Trade Deadline. At that time, Manaea had made just two starts for Northwest Arkansas, neither of which went particularly well.

But things clicked for Manaea at Double-A Midland following the trade, as he proceeded to go 6-0 with a 1.90 ERA and 51 strikeouts in 42 2/3 innings for the Rockhounds across seven starts. He then built upon his strong finish with an impressive showing in the Arizona Fall League, pacing the circuit with 33 strikeouts while pitching to a 3.86 ERA over six starts.

Zinkie on Manaea being called up

Manaea possesses a 90-96 mph fastball that will sneak on opposing hitters on account of his deceptive delivery and extension toward the plate. Some scouts worried about his ability to maintain velocity deep into starts, though that hasn't been a problem for him this season. Manaea pairs his heater with a slider that flashes plus at its best, but tends to vary in terms of pace and action. The combination is extremely effective against left-handed hitters, whom he's held to a paltry .077 average in 2016. Manaea also continues to show improving feel for his changeup, which he turns over nicely to generate late-fading action, and it's become a legitimate weapon for him against right-handed hitters.

But what makes Manaea special -- in addition to his three average-or-better pitches, that is -- is his knack for inducing swings and misses as well as weak contact. The left-hander has averaged 10.8 strikeouts per nine innings over 214 career frames, and he's surrendered just 11 home runs (0.5 HR/9) in that span. Manaea's strike-throwing ability and command also have improved in the upper Minors, as his 2.0 BB/9 rate at Nashville this season -- down from 3.1 BB/9 in 2015 and 4.0 in '14 -- represents the best mark of his young career. All in all, Manaea has the makings of a mid-rotation starter, provided he can stay healthy.

Manaea will make his big league debut on Friday in the place of Eric Surkamp, who was demoted to Nashville at the beginning of the week. While it's yet to be seen whether or not Manaea will remain with the A's beyond the one start, there's no questioning that he has the stuff to make both an immediate and long-term impact on Oakland's rotation.

Mike Rosenbaum is a reporter for MLB.com. Follow him on Twitter at @GoldenSombrero. This story was not subject to the approval of Major League Baseball or its clubs.