The Mariners' first round pick in 2010, righthander Taijuan Walker looks like a number one starter on almost any MLB team. On the Mariners, that probably makes him a number three, or maybe two-and-a-half. (This team's pitching depth in the minors is just plain sick.

Walker's progress looks to have taken a step back in 2012, as he struggled at times in Jackson, but once you account for his aggressive promotion, a 4.69 ERA / 1.374 WHIP doesn't look so bad for a nineteen year old in AA ball. He did carry a heavy workload for a teenager, pushing through 127 innings of work while striking out almost one hitter every inning.

Walker works mainly with a 94mph darting fastball that has great late movement, and when he mixes in a sometimes-effective straight change at 82mph, the fastball is nearly unhittable. His breaking pitch is a slurvy curve that isn't yet ready for regular use, but he'll have time to develop. Walker has higher upside (and higher risk) than either Hultzen or Paxton, but he's also a lot younger, and will probably take longer to realize his potential. He needs to start the year back in AA, but if he makes progress, it's not unreasonable to expect a late-season look in Seattle. Mid-2014 looks like his real callup date, however.