Peter Morgan Alonso
- Bats Right, Throws Right
- Height 6' 3", Weight 245 lb.
- School University of Florida
- High School H. B. Plant High School
- Debut March 28, 2019
First baseman Pete Alonso was selected by the New York Mets in the 2nd round of the 2016 amateur draft, out of the University of Florida. He did not waste time having an impact in professional baseball, as in his first season, in 2016, he batted .321 with 5 homers and 21 RBIs in 30 games for the Brooklyn Cyclones of the New York-Penn League. he began the 2017 season with the St. Lucie Mets of the Florida State League, where he hit .286 in 82 games, earning a late-year promotion to the Binghamton Rumble Ponies of the Eastern League. there, he hit .311 in 11 games to finish with a batting line of .289/.359/.524 with 27 doubles and 18 homers in 93 games.
He confirmed his status as a prime hitting prospect in the first half of the 2018 season, when he hit .314 in 65 games for Binghamton, earning another promotion, this time to the Las Vegas 51s of the Pacific Coast League. With Mets fans clamoring for his call-up with veteran Adrian Gonzalez, who was starting up in the Big Apple, showing he was clearly washed up, he was named to the United States team for the 2018 Futures Game. He replaced Nate Lowe at first base in mid-game and on the 7th inning hit a monstrous home run off Adonis Medina on a full count after a long battle. It was good for two runs and sealed a 10-6 win for the U.S. In 132 games between Binghamton and Las Vegas, he hit .285/.395/.571 with 31 doubles, 36 homers and 119 RBIs. In earlier times, this would have earned him a September call-up to the Big Apple, but the Mets were wary of service times issues and decided not to give him a look.
He was one of the big stories of spring training for the Mets in 2019, as he continued to hit extremely well, but the Mets were still playing coy, leaning towards having him start the year in AAA and only calling him up after a couple of weeks, after just enough time to delay his eligibility for salary arbitration by a year, just as the Chicago Cubs had done with Kris Bryant a few years earlier. This was becoming an ever-more-serious issue for the Players Association and its head, Tony Clark stated it clearly: "Seeing what players are going through where their service time is being manipulated, on the front end and/or in the middle, is a concern, has been a concern and will continue to be a concern." His concern was that teams were not putting their best players on the field because of such financial concerns, depriving fans of the best possible competition. However, he managed to impress the Mets enough to have them waive these concerns, having him start the year on the major league roster. He made his debut on Opening Day, March 28th, starting at first base and going 1 for 4 in a 2-0 win over the Washington Nationals. He hit his first career homer on April 1st off Drew Steckenrider of the Miami Marlins. It came with two men on in the 9th, after the Mets had broken through to take a 4-3 lead, and confirmed his team's 7-3 win. He was named the National League Rookie of the Month for April after hitting .292 with 9 homers and 26 RBIs during the month. On May 29th, he had another two-homer game in a 9-8 loss to the Los Angeles Dodgers, giving him 10 for the month - a new Mets rookie record - and 19 for the year. This tied him with Mark McGwire for most homers before June 1st. On June 22nd, his 26th homer tied the Mets rookie record for a season held by Darryl Strawberry, set in 1983; he also broke Cody Bellinger's NL record for most homers before the All-Star Game. He set a new Mets rookie record with another homer the next day. He was named to the 2019 All-Star Game as a result of his great first half and was again named NL Rookie of the Month, for June. He hit homer #30 in the Mets' last game before the break, on July 7th. He won the annual Home Run Derby staged at Progressive Field on July 8th, outhitting Vladimir Guerrero Jr. in the final round in a battle of rookies. The $1 million prize he took home more than doubled his annual salary. He hit his 35th homer of the year on August 5th, in a 5-4 win over the Marlins that put the Mets above .500 for the first time since May 2nd. On August 15th, he tied the NL rookie record set by Bellinger in 2017 with his 39th homer, and set a new record with #40 on August 18th. On August 24th, he tied the franchise record with his 41st homer, equaling the mark shared by Todd Hundley and Carlos Beltran. His 42nd homer on August 26th gave him sole possession of the team record. He kept on hitting long balls after that, reaching another milestone on September 20th with number 50. On September 27th, he hit number 52, tying the all-time rookie record set by Aaron Judge two years earlier. He claimed sole possession of the record the next day when he hit #53 off Mike Foltynewicz of the Atlanta Braves in the Mets' penultimate game. He was named the league's Rookie of the Month again in September, book-ending his season with the award. His final stats were 161 games, a .260 average, 30 doubles, 53 homers, 103 runs and 120 RBIs, good for an OPS+ of 148.
- NL All-Star (2019)
- NL Home Runs Leader (2019)
- 20-Home Run Seasons: 1 (2019)
- 30-Home Run Seasons: 1 (2019)
- 40-Home Run Seasons: 1 (2019)
- 50-Home Run Seasons: 1 (2019)
- 100 RBI Seasons: 1 (2019)
- 100 Runs Scored Seasons: 1 (2019)
- Home runs by a rookie: 53 in 2019
- Mark Feinsand: "Polar Bear Pete! Alonso wins Home Run Derby: Mets slugger defeats Vlad Jr. in finals to win $1 million grand prize", mlb.com, July 9, 2019. 
- Gabe Lacques: "Pete Alonso's dream season rolls on with Home Run Derby title, All-Star Game: 'I'm living a fantasy right now'", USA Today, July 8, 2019. 
- Jonathan Mayo: "With an All-Star first, Alonso makes an impact: Mets slugger makes history by driving in multiple runs; deGrom throws perfect inning", mlb.com, July 10, 2019. 
- Bob Nightengale: "Pete Alonso, who sets Mets' single-season home run record, is living a 'dream come true'", USA Today, August 28, 2019. 
- Justin Toscano: "Mets' Pete Alonso breaks Aaron Judge's single-season rookie record with 53rd home run", USA Today, September 28, 2019.