Taijuan Walker perched himself among the best pitching prospects with his efforts the past two years. The team plans to make him a full time member of the rotation after a three start cup of coffee with the Mariners last fall. His manager has already as much as confirmed it. His scouting snapshot is an athletic pitcher who throws hard easily and can repeat his delivery into the later innings.
Walker pitched most of 2012 in Double-A as the youngest hurler in the Southern League. He completely bypassed High-A making for a stiff adjustment. With a 4.04 FIP and 2.36 K/BB he was not dominant, but considering he was only twenty it was enough to turn heads. Many future aces struggled initially in Double-A, this list compiled by Fangraphs puts Walker in good company.
Walker returned to Jackson in 2013 and proceeded to dominate the Southern League with a 10.29 K/BB and 3.13 FIP. He earned a midyear promotion to Triple-A and kept his strikeout rate over 10.0. More walks decreased his K/BB to 2.37 however. In the higher level his BABIP against increased from .259 to .331, but his FIP only jumped to 3.62.
Minor league batted ball data from 2013 paints a very promising picture. Walker kept 47.77% of balls in play on the ground against 27.97% fly balls. This is far more predictive than his 0.94 GB/FB in his three major league starts. He also limited minor league hitters to a 15.84% line drive rate. This suggests he was able to dominate most hitters and induce weaker contact when he was not striking them out.
While none of Walker’s Mariner stats are drawn from a large enough sample to say anything with certainty, some patterns did emerge. His contact rates were better than league average, but he did not induce as much chasing as other pitchers. This could easily be because his raw stuff is impressive, but he relied heavily on his fastball and his breaking pitches are still works in progress. That would also fit the scouting consensus.
After throwing 156.1 innings in 2013 a standard jump would let Walker make almost a full season’s worth of starts. Considering how many pitchers went on the DL last year, avoiding Walker because he may be held back for a handful of starts does not make sense. The far bigger issue is control, a common problem among young pitchers. Walker’s best BB% is 8.9%, accomplished his second time through Double-A. While better baserunner prevention can come in time, it is unlikely to emerge in a rookie season. Steamer, Oliver, and ZiPS all project Walker for an ERA over 4.00 and a K/BB hovering around 2.00. He is long gone in dynasty leagues, and does not look particularly useful in redraft given the depth at SP. For those really wishing to gamble on his upside, Chris Archer’s 2013 may approximate a best-case scenario. The Ray rode a .253 BABIP against to a 3.22 ERA and a Razzball-calculated $6.20 return in 128.2 IP.