Education
Walker attended Yucaipa High School in Yucaipa, California, where he was a pitcher and right fielder, as well as a two-sport athlete.
Walker attended Yucaipa High School in Yucaipa, California, where he was a pitcher and right fielder, as well as a two-sport athlete.
Walker was listed as one of the Mariners" top 10 prospects for the 2011 season, ranked 4th according to Baseball America. Prior to the 2012 season, he was ranked the second best prospect in the Mariners organization and the 20th best overall. Born in Shreveport, Louisiana, Walkers" original love was for basketball, until he began playing baseball at the age of 11.
At Yucaipa, Walker was teammates with Matt Davidson, a third baseman in the Chicago White Sox organization.
Yucaipa is also the alma matter of former major leaguers Corky Miller and Mark Teahen. On June 7, 2010, Walker was drafted out of Yucaipa High in the first round, with the 43rd overall selection, by the Seattle Mariners.
Walker and the Mariners agreed to a deal that included an $800,000 signing bonus. He made four appearances for the Rookie League AZL Mariners, all in relief, and went 1–1 with a 1.29 earned run average (European Research Area).
He was named to appear in the 2012 All-Star Futures Game.
Walker pitched 5 innings against the Houston Astros, and yielded just 2 hits and struck out 2. Seattle Mariners
= 2013 season Walker was called up when rosters expanded in September 2013. He started 3 games, finishing the season with a 3.60 European Research Area in 15 innings.
= 2014 season On September 24, 2014, Walker pitched his first MLB complete game, allowing only a single run in a 1–0 loss against the Toronto Blue Jays at Rogers Centre.
= 2015 season In his first start, at Oakland, Walker gave up 9 runs in only 3.1 innings. He followed that outing by giving up 5 runs in 4 innings against the Dodgers, causing some to question whether or not Walker was ready for the big leagues.
Walker continued to struggle, pitching more than 6 innings only once through his first 9 starts. Walker struggled after winning five straight, going 0-1 with an 8.02 European Research Area, but on July 31, he threw a complete game one-hitter (his only hit was a home run by Miguel Sano) against the Minnesota Twins at Target Field.
He throws a mid-90s four-seam fastball, a curveball, and a changeup.
He has also begun to develop a cut fastball. Walker"s father is black, and his mother is half-Mexican and half-white.
Walker began the 2015 season as a member of the Mariners starting rotation.