Outfielder Alex Jackson was in consideration for the first overall pick in 2014, didn't make it out of the top 10 and was supposed to be on the fast track to the majors by now. Instead, Seattle flipped him (with a player to be named later) for two lower-tier pitching prospects, as Atlanta cashes in some of its pitching depth to roll the dice on a longshot bat who still has a high ceiling if he can get out of his current rut.
Seattle turned the page on the sixth overall pick in the 2014 draft before it even had to put the player on its 40-man roster. The Mariners took Jackson, a high school catcher with power and what appeared to be a promising hit tool, and moved him immediately to right field, because they felt his bat was good enough that he should play every day.
His first summer ended when he took a ball off his face while playing the outfield, and since then he just hasn't hit at all, striking out in nearly 30 percent of his plate appearances across two seasons in low-A and short-season ball, showing much less power than anticipated as well.
Jackson's approach has been poor, and he's been leading too much with his elbow, causing him to over-rotate and pull or hook everything to the left side. Some of this is fixable if the player is willing, and I think the Mariners started to lose patience after a second year of minimal progress. It makes all the sense in the world for Atlanta to trade from its stock of pitching prospects to add a high-ceiling, out-of-favor player like Jackson, who will turn 21 on Christmas Day and hasn't lost anything physically that would make it impossible for him to restore his value.
In exchange for Jackson, the Mariners get two lower-ceiling pitching prospects who have a better chance to help the major-league team in the near future.
Max Povse is a giant (6-foot-8) strike thrower with an average fastball and plus changeup. He has shown better velocity in the past, but it fluctuated in 2016, and he's never had an average breaking ball. He's probably a back-end starter, maybe one who can help in 2017 given his success through double-A. The history of starters this tall staying healthy isn't great, although Povse has been healthy in his two-plus years in pro ball.
Rob Whalen is a sinker-slider guy with fringy stuff who doesn't miss enough bats, probably a triple-A depth starter or future reliever. It's definitely a letdown considering where they drafted Jackson, but if internally they'd come to the conclusion that their former No. 1 prospect was never going to develop, then I can at least understand trading him for players who could help their team in 2017.