Joseph Anthony Mancini
- Bats Right, Throws Right
- Height 6' 4", Weight 215 lb.
- School University of Notre Dame
- High School Winter Haven High School
- Debut September 20, 2016
Trey Mancini homered in his major league debut for the Baltimore Orioles against the Boston Red Sox on September 20, 2016. He connected for a solo shot off Eduardo Rodriguez in the 5th inning, but the Orioles lost the game, 5-2. He then homered in his next two games as well to become the first player in Orioles history to accomplish the feat. He hit .357 with the 3 homers and 5 RBIs in 5 games in his first taste of the majors, and was on the team's roster for the Wild Card Game, although he did not play.
He made the team out of spring training in 2017 although it was not clear at first how much playing time he would see. He quickly gave indications that he should be in the line-up often, however, as he had a pair of two-homer games over the span of three games in early April, turning the trick against the Boston Red Sox on April 12th, and again against the Toronto Blue Jays on April 16th. In that second game, he victimized Ryan Tepera with a three-run shot in the 6th and added a solo blast off Matt Dermody in the 8th. That gave him 7 homers in his first 12 major league games, matching the record pace set by Dino Restelli in 1949 and Trevor Story the year before. He ended up playing 147 games, split between left field, first base and DH, and hit .293 with 24 homers and 78 RBIs. His OPS+ was an excellent 120. He finished third in the voting for the 2017 American League Rookie of the Year Award, which was won by Aaron Judge.
Mancini's strong rookie campaign secured his spot in the Orioles' line-up for the future, but unfortunately for him, just about everyone else who was part of the Birds' playoff team in 2016 was soon gone as the team went through a deep process of reconstruction. On-field the results were an ungodly number of losses in both 2018 and 2019 as the team became the patsies every one else was beating up on. Mancini had the dubious honor of being the team's most-used player those two years, playing 156 and 154 games. In 2018, he slumped to .242 and 55 RBIs although he did hit 24 homers again, playing the same three positions as the year before. In 2019, he moved over to right field, but also saw time at first base and DH as he was in the starting line-up nearly everyday. In a year when home runs were flying out of the park at Camden Yards in record numbers, he hit 35 long balls, to go along with 38 doubles, 97 RBIs and a .291 batting average. His OPS+ was 135, although he went largely under the radar given how bad his team was.
In spring training in 2020, he was affected by flu-like symptoms and was sent home in early March for a "non-baseball medical procedure" among speculation that he had been infected by the coronavirus that was claiming a growing number of victims around the world and in the U.S. However, it turned out that what was afflicting him was a malignant tumor in his colon, which was successfully removed. The season was suspended, and there was hope that as a result he would not miss any time; however, even if the operation was successful, he still needed to undergo chemotherapy for six months, which forced him to miss the entire season. He used the time off to set up the Trey Mancini Foundation, whose objective is to "support those who are facing illness, empower those suffering from emotional trauma and provide assistance to those experiencing hardship."
He was ready to return to work when spring started in 2021, the plan being for him to alternate between first base and designated hitter to begin things. Crowds were still limited to 25% of capacity when the O's played their first Grapefruit League game on February 28th, but everyone present, including both dugouts, gave him a standing ovation when he first came to bat. He was the Orioles' Opening Day first baseman against the Boston Red Sox on April 2nd and his comeback was a true feel-good story that season: on May 19th, he hit two homers and drove in 5 runs to take over the major league RBI lead with 38, hitting better than anyone could have anticipated. While he was not named to the All-Star team and would have been a defensible choice if teammate Cedric Mullins had not been in the midst of a break-out season, he was still invited to the Home Run Derby. While more a line-drive hitter than a pure slugger, he acquitted himself well, making it all the way to the final round, where he hit an impressive total of 22 homers in his allotted time, but it was still not enough to defeat a smoking hot Pete Alonso, who successfully defended his title.
- 2017 Topps All-Star Rookie Team
- 20-Home Run Seasons: 3 (2017-2019)
- 30-Home Run Seasons: 1 (2019)
- 100 Runs Scored Seasons: 1 (2019)
- Chris Bumbaca: "Baltimore Orioles' Trey Mancini will likely miss 2020 season due to chemotherapy treatment", USA Today, April 28, 2020. 
- Do-Hyoung Park: "'It was surreal': Mancini finishes 2nd in Derby; Orioles slugger's comeback year continues with impressive showing at Coors Field", mlb.com, July 13, 2021. 
- Joe Trezza: "Mancini recovering post-surgery to remove tumor", mlb.com, March 12, 2020. 
- Joe Trezza: "Mancini's foundation eyes big impact in city", mlb.com, January 25, 2021. 
- Joe Trezza: "Inside Mancini's inspiring return to baseball", mlb.com, March 29, 2021.