5 former "Can't Miss" Mariners prospects that ended up doing just that

3. Alex Jackson, Catcher

Alex Jackson was the top prep bat to come out in the 2014 MLB Draft, and the Mariners selected him with the 6th overall pick. He was a catcher, but the Mariners viewed Jackson as an outfielder and drafted him as such. He was the 6th player from Rancho Bernardo High School in San Diego to be drafted in the first round since 1995. Jackson was athletic enough to play the outfield and had a cannon of an arm worthy of playing Right Field.

The key problem for Jackson in a Mariners uniform was his bat. Jackson did not advance past A ball for the Mariners in his 3 years in Seattle. in those 3 seasons, he struck out 32.5 % of his ABs, while walking 10% of the time. He hit just .233 during this time, and ended up being traded to the Atlanta Braves in the offseason before the 2018 season. He actually made his MLB debut in 2019, going hitless in his 13 ABs. He has bounced around the league since, playing for the Marlins, Brewers and is now a member of the Tampa Bay Rays.

Jackson was a key miss for the Mariners, one that did former Mariners GM Jack Zduriencik in. 2014 would be the last draft before the Mariners fired Jack Z, and the M's would move on to hire Jerry Dipoto. While Jack may be blamed for drafting Jackson where he did, nearly every GM would have done the same thing. Jackson was the top high school bat in the entire draft. But hindsight being what it is, the Mariners could have used that pick to select Aaron Nola, Trea Turner, or Matt Chapman.