Milwaukee Milkmen sign former Giants top prospect Joan Gregorio

In comparison to Major League Baseball, member organizations of the independent American Association of Professional Baseball have a different set of rules that they are required to operate under when it comes to roster-building. There is a 23 active player limit once the regular season begins, and of those 23, only a maximum of five can fit the description of “veteran” classification — someone with six or more years of professional experience who will be playing in their age-27 season or older. Because of those restrictions and the way the league’s salary cap is structured, clubs generally need to count on their veterans to be the most impactful players on the team.

The Milwaukee Milkmen believe that right-hander Joan Gregorio has that capability.

Recently turned 28, Gregorio got his professional career started a decade ago back in early 2010 when he signed as an international free agent with the San Francisco Giants. It didn’t take long for him to start earning notoriety from scouts. After a successful debut in the Dominican Summer League, the Giants moved Gregorio stateside, where he was named of the top-20 prospects in the Arizona League by Baseball America after the 2011 season. He continued to develop in short-season ball for the next couple of seasons as he learned how to control his gangly 6’7” frame, and after posting a 4.00 ERA and 2.45 FIP with an 84:17 K/BB ratio in 69.2 innings for Augusta in 2013, he made his first appearance on BA’s top prospect list for the Giants, checking in at #17.

That would begin a run of five consecutive seasons where Gregorio was ranked as a top prospect within San Francisco’s org by Baseball America. He posted a 4.37 ERA while punching out more than a batter per inning while splitting the 2014 season between A-ball and Class A-Advanced, which was enough to convince the front office to add Joan to their 40-man roster in order to protect him from Rule 5 Draft eligibility. During the ensuing offseason, Gregorio worked to add some good weight and strength to his frame in addition to cleaning up his mechanics and pitching motion for more consistent control. He started the 2015 season in the bullpen for Double-A Richmond before moving into the starting rotation for the second half of the season, and delivered a sparkling 3.09 ERA alongside an excellent 80 DRA- across 78.2 frames. He punched out 72 batters while walking 32 and allowed only six home runs all season.

Gregorio was once again stellar in Double-A to begin the season in 2016, cruising to a 2.33 ERA and outstanding 43 DRA- in five starts before earning his first call-up to the highest level of the minors. He finished out the year by making 21 starts for Sacramento of the Pacific Coast League, and while his 5.28 ERA suggests that he struggled, scouts nonetheless came away impressed with what Joan brought to the mound. He struck out 122 batters in 107.1 innings in Triple-A while issuing only 43 walks, and a FIP of 4.34 suggests that his earned run average should have actually been nearly a full run lower than it wound up being.

Gregorio seemed to be in the process of taking that “next step” the following year in 2017, authoring a 3.04 ERA across his first 13 starts and 74.0 innings back in Triple-A. He seemed destined to make his MLB debut before long, that is, until he was suspended under the Joint Drug Agreement. That cost him the rest of his season and a shot at a September call-up. Out of minor league options, the Giants outrighted Gregorio off their 40-man roster prior to the start of the 2018 season. He began the year back in Triple-A but went on the disabled list within the first few weeks of the season. He wound up appearing in only five games and tossing 7.0 innings during the entire season, and after the campaign concluded, he was allowed to depart the organization via free agency.

Gregorio found himself pitching in Mexico as he worked his way back to full health in 2019, landing with Piratas de Campeche in a bullpen role. He struggled to the tune of a 10.93 ERA across 14.0 innings, but pitching at extreme altitudes in an environment heavily tilted towards offense makes those numbers difficult to evaluate. Now that he’s fully healthy, Gregorio is primed to make a return to the starting rotation for the Milkmen in the American Association during the upcoming summer.

Gregorio is an imposing presence on the mound, now listed at 6’8” tall with a chiseled, 264 pound frame. He comes at batters from a unique, low three-quarters arm slot. He has a slow, funky delivery that adds deception to his offerings. There is little effort to his pitching motion and the ball looks easy coming out of his hand, but because of his significant arm speed, it is almost surprising how much velocity he is able to generate. During his time as a prospect, Gregorio’s fastball topped out in the 94-95 MPH range while he was pitching as a starter, but with a much greater perceived velocity to hitters thanks to the tremendous extension that is produced by his massive, long-limbed frame. In his bullpen sessions this winter, however, he has been clocked as high as 97-98 MPH.

Gregorio’s mid-80s slider is his best secondary offering, one that he uses to generate swings-and-misses — especially when located to his gloveside — thanks to the spin and shape of the pitch. He also throws a changeup that typically sits in the 85-86 MPH range, which is a pitch that has improved over the years as Gregorio has gotten used to throwing it with more conviction. All of his offerings play up due to his funky delivery and prodigious extension, as well as the high spin rates that he is naturally able to produce.

As is the case for most tall pitchers, getting all of his levers lined up properly can still be challenging at times for Gregorio, leading to occasional lapses in control. But he has continually improved his ability to command the zone throughout his time as a pro and throws more than enough strikes to be effective. When you put it all together, Joan Gregorio’s profile looks like that of a possible top-of-the-rotation presence in the American Association. His career ERA of 2.90 at the Double-A level — the closest affiliated comparison — should offer a pretty good inclination as to just how much impact he could provide to the Cream City’s independent professional nine in 2020.

Statistics courtesy of Fangraphs, Baseball-Reference, and Baseball Prospectus