With alternate camps coming to an end, MLB Pipeline is recapping the development highlights for the prospects involved for each organization.

Top position prospect: Ronny Mauricio, SS (No. 1/MLB No. 57)
The Mets initially chose not to include any of their younger, lower-level top prospects in their 60-man player pool when it was first released in July, instead giving those coveted roster spots to players capable of helping the big league roster in 2020. But as the season unfolded and spots at the team’s alternate training site in Brooklyn became available, those young players were the first to get the call.

Mauricio, 19, was among the first additions at the Mets’ alternate training site, receiving an assignment on Aug. 16. After slashing .268/.307/.357 with 29 extra-base hits in the Class A South Atlantic League last year, the switch-hitting shortstop furthered his development on both sides of the ball during his time in Brooklyn.

“He’s a really impressive young player with a lot of great tools,” said Jared Banner, the Mets’ executive director of player development. “Our focus is just on refining his game, recognizing his strengths and areas where he needs to improve, and then having him attack both on a daily basis.”

What’s more, Mauricio, whom the club signed for $2.1 million in July 2017, has continued to add strength to his ultra-athletic 6-foot-3, 166-pound frame. That remaining projection, on top of the physical gains he’s already made, is exactly why evaluators are so high on Mauricio’s power potential, with some even pegging him for plus game power at maturity.

“He’s one of those guys where every time you see him, he looks bigger and stronger,” said Banner. “It’s always impressive to see him ... he looks more and more like a big leaguer every day, and he’s only going to get stronger and more athletic.”

Top pitching prospect: Matthew Allan, RHP (No. 4)
The Mets landed a trio of high-ceiling high school players early in the 2019 Draft, taking projectable right-handed pitchers Josh Wolf and Allan in the second and third rounds, respectively, after selecting Brett Baty with the No. 12 overall pick. Allan signed for $2.9 million, roughly four times slot value for the No. 89 overall pick, and immediately showed why he was viewed as one of the nation’s top prep hurlers by reaching Class A Short Season Brooklyn during an electric pro debut.

Allan’s plus fastball-curveball pairing looked as good as ever this summer at the Brooklyn site, and the 19-year-old righty received rave reviews from club officials for how he competed against Triple-A and Major League-quality hitters. But what really stood out to Banner and the rest of the Mets’ player development staff was Allan’s improved changeup, a pitch he rarely needed to throw in his first taste of pro ball, let alone as a prep.

“It’s really developed a lot,” noted Banner. “He’s obviously still throwing the ball very hard, with a lot of life through the zone, but the changeup has really emerged. He has a chance for three plus pitches.”

Youngest prospect: Francisco Alvarez, C (No. 2/MLB No. 58)
Alvarez entered the 2020 season with as much hype as any Mets prospect after he batted .312/.407/.510 with seven homers across two levels, including the Rookie Appalachian League, in his pro debut at age 17. Coming just a year after the Venezuelan catcher had signed with the club for $2.7 million, Alvarez’s breakout performance also offered the Mets a glimpse of his bright future. Unsurprisingly, the organization jumped at the chance to add him to the alternate site squad when the opportunity arose in August.

“We were thrilled to get him in there,” Banner acknowledged. “A catcher his age getting a chance to work with some older pitchers and pick their brains on things like how to call a game and prepare ... I think it was a very valuable time for him.”

2020 Draft picks
None of the Mets’ five picks from the 2020 Draft saw time at the team’s alternate training site in 2020. 

Pleasant developments
Brett Baty (No. 3/MLB No. 88) and 2017 second-round pick Mark Vientos (No. 7) are two of the better, if not the best power hitters in the organization, with both players standing out for their physicality as well as their innate ability to impact the ball. When they arrived at the Brooklyn site in late August, it was clear to those within the organization that both players had put in a lot of work to improve their strength during the shutdown -- and that was before each guy recorded an extra-base hit in his first game at-bat.

“It’s pole-to-pole power,” said Banner about the left-handed-hitting Baty, who arrived at the alternate site looking leaner than the previous year. As for Vientos, who clubbed 12 homers and 27 doubles last year in his first full season, Banner noted that the 20-year-old prospect was “hitting the ball out of the ballpark the other way.”

The Mets also are optimistic that Baty and Vientos will be able to stick at the hot corner defensively and note that both were noticeably better in the field this summer than the previous year.

“They’re both athletic, with good hands and strong arms, and they both have good internal clocks,” said Banner. “Of course, we need to refine a lot of the little details that come with playing defense at the highest levels, but they both have the makings to be high-quality defensive third basemen in the big leagues.”

The Mets added Thomas Szapucki to their 40-man roster last November after the former fifth-round pick (2015) returned from a nearly 22-month absence due to Tommy John surgery to post a 2.63 ERA with 72 strikeouts in 61 2/3 innings across three levels, including Double-A Binghamton. The campaign marked a new career-high workload for the 24-year-old southpaw, after injuries had limited him to just 83 1/3 frames in his first four seasons.

Pitching at the alternate site this summer, Szapucki continued to refine his deceptive low-90s fastball and plus curveball, showing more consistency with each pitch. His biggest gains, however, were with his changeup, a pitch that largely had been viewed as a below-average offering going into the year.

“He really progressed with it,” said Banner. “It gives him a third weapon, along with the fastball and curveball, a weapon that he can use against right-handed hitters.”