McKay, the fourth-overall pick in last year's draft, made his professional playing debut in the short-season New York-Penn League last year and will start this season with the Bowling Green Hot Rods in the Midwest League. It will be interesting to see how his workload shakes out over the course of a full pro season, and of course, how well he does on the field.
In limited play last year, McKay made six starts as a pitcher, 21 starts as a first baseman, and nine starts as a designated hitter. The left-hander posted a 1.80 ERA, 21 strikeouts and five walks in 20 innings on the mound, and batted .232 with 4 HR and 22 RBI at the plate. Obviously he had more success as a pitcher than a hitter, but still was impressive enough all-around to get named by Baseball America as the top prospect in the New York-Penn League last year.
(In those rankings, BA wrote that McKay's playing schedule was pitcher on Sunday, DH on Monday, first base on Tuesday, off Wednesday for pitching side session, DH on Thursday, and first base on Friday and Saturday. My guess is his playing schedule will follow a similar order with the Hot Rods, at least until (if) coaches determine it needs to be amended in some way.)
McKay is considered a legitimate prospect as both a pitcher and a hitter. Both Baseball America and MLB Pipeline have him ranked as the third-best prospect in the Rays organization; MLB Pipeline says he's "regarded as the best two-way draft prospect since Dave Winfield in 1973." As a hitter, Baseball America says, McKay "has a simple, sound swing that generates line drives to all fields" and has "above-average raw power that could generate 20-plus home runs as he adds more loft to his swing." As a pitcher, McKay has three offerings, all of which are considered above-average: a fastball that sits in the low-to-mid 90s, a curveball, and a cutter.
Want to read more about McKay? I highly recommend this article by Tampa Bay Times writer Marc Topkin that looks at McKay's motivations and challenges, as well as the risks involved with developing a two-way player.