The Mariners announced that they will promote right-hander Taijuan Walker in time to make his major league debut on Friday against the Astros. Walker, 21, is the M's undisputed top pitching prospect.
This year, Walker was rated as the third-best prospect in the nation by Jonathan Mayo of MLB.com, No. 9 by Keith Law of ESPN.com, and the 18th best prospect by Baseball America, BA's 2013 handbook, which put Walker as second only to Mike Zunino in the M's system, describes the youngster as a "premium athlete with an ideal pitcher's frame." Walker projects as a potential ace and his potential showed through 2012, even though his Double-A stats didn't quite support that.
In 25 starts at the Double-A and Triple-A level this season, Walker posted a 2.93 ERA with 10.2 K/9 and 3.6 BB/9. His late August promotion means that the M's can keep him under club control through 2019 without triggering an additional trip through arbitration.