Hader has rocketed through the upper levels of the minors over the past two seasons, rising from High-A in 2014 to Triple-A in 2016 -- he was even considered for a spot start with the Brewers late in the season, but it never came to fruition. The lanky lefty struck out a ludicrous 161 batters over just 126 innings across Double-A and Triple-A, proving his pitches aren't only capable of fooling the raw youngsters of the lower minors. There are still questions surrounding the quality of his changeup and command, and at 6-foot-3 and 185 pounds, many of the same concerns that surrounded Chris Sale's future durability as a young prospect have resurfaced with Hader. Despite those worries, Hader's prospect stock has ballooned over the past two seasons as he has turned into one of the gems of the Brewers' restocked farm system. He should finally be allowed to test out his plus fastball and plus slider against big league hitters sometime this summer.

A 19th-round pick in 2012, Hader was barely on the prospect radar before the Brewers acquired him as part of last summer's Carlos Gomez trade. Hader was sharp in Double-A, as he posted a 3.03 ERA in 104 innings between the Brewers and Astros systems, but he really shined in the Arizona Fall League, where had one of the best performances of any pitcher, posting a 0.56 ERA with 19 strikeouts in 16 innings. Hader has an unorthodox delivery and there are questions about his durability, but he has shown huge upside over the past calendar year or so and he's now one of the top prospects in the Brewers' system. Beginning the 2016 season as a 22-year-old, Hader will probably start in Triple-A. The Brewers have a glut of fringey starters right now, so a lot would have to happen for Hader to arrive in the major leagues in 2016, with mid-2017 seeming like a better estimated time of arrival.

Acquired from Baltimore in the 2013 Bud Norris trade, Hader earned a promotion to Double-A last season as a 20-year-old after posting outstanding numbers in the hitter-friendly California League. In 22 games (15 starts) with High-A Lancaster, the 6-foot-3, 160-pound lefty went 9-2 with a 2.70 ERA, 1.11 WHIP and 112:38 K:BB over 103.1 innings. While his big league future as a starter or long man out of the bullpen remains unclear due to his skinny frame and potential for breaking down deeper in outings, how Hader performs this season -- likely in Double-A with a potential promotion to Triple-A if things go well -- should better determine his path to the majors.

Hader, a 19-year-old left-handed starter, was acquired by the Astros in the trade that sent Bud Norris to Baltimore. Between both clubs, he accumulated 22 starts in Low-A ball, posting a 2.77 ERA with a 95:54 K:BB ratio over 107.1 innings while earning South Atlantic League All-Star honors. Hader needs to work on the command of his three pitches - a low-90s fastball, changeup and curve - but he has plenty of time to do that as he grows into his 6-foot-3, 160-pound frame. He has the stuff to advance quickly through the Astros' system, but he's likely a few seasons away from contributing in Houston.