On May 24, 2013, Tromp signed with the Cincinnati Reds organization as an international free agent. He was assigned to the AZL Reds, where he spent the season. In 2014, Tromp spent time between the AZL Reds and the Single-A Dayton Dragons. He batted .311/.345/.472 with three home runs and 13 RBIs in 106 at bats.[1]
In 2015, Tromp played for Dayton and a game for the Triple-A Louisville Bats. In 2016, Tromp played the entire season for the advanced Single-A Daytona Tortugas.
Tromp spent 2017 with Daytona and the Double-A Pensacola Blue Wahoos. He was invited to spring training for the 2018 season, but did not make the club and played in 25 games for Pensacola and 53 for Triple-A Louisville on the year.
In 2019, he spent time with the AZL Reds and Louisville. He batted .280/.397/.568 with nine home runs and 37 RBIs in 125 at bats.[1] He elected free agency on November 4, 2019.
On January 6, 2020, Tromp signed a minor league contract with the San Francisco Giants organization.[2]
On July 28, 2020, the Giants called him up to MLB for the first time.[3][4] Tromp made his MLB debut on July 29 against the San Diego Padres and went hitless over four at bats.[5] Tromp hit his first home run in the majors on August 2, in a 9–5 loss to the Texas Rangers.[6] On December 2, Tromp was nontendered by the Giants.[7] On December 9, Tromp re-signed with the Giants on a major league contract.[8] On September 18, 2021, Tromp was designated for assignment by the Giants after hitting .222 during 18 plate appearances.[9]
On September 21, 2021, the Atlanta Braves claimed Tromp off waivers from San Francisco, and optioned him to the Triple-A Gwinnett Stripers.[10][11] On April 12, 2022, Tromp was designated for assignment by the Braves.[12] He cleared waivers and was outrighted to Triple-A Gwinnett Stripers on April 19.
On August 6, 2022, Tromp was called up to Atlanta as a backup catcher, following an injury to Travis d'Arnaud.[13][14] On August 13, Tromp had a three-hit, three RBI performance in his first game started for the Braves against the Miami Marlins.[15] This was the only appearance Tromp made with Atlanta during the 2022 season.[16] Tromp was recalled to the major leagues on April 9, 2023,[17] after d'Arnaud was injured in a game the previous day.[18] On May 8, he was optioned to the Gwinnett Stripers.[19] Tromp played in 6 games for Atlanta in 2023, going 2–for–16 (.125) with one RBI. On November 17, Tromp was non–tendered and became a free agent.
On November 22, 2023, Tromp re–signed with the Braves on a minor league contract.[20] On March 30, 2024, Tromp was selected to the active roster following an injury to Sean Murphy.[21]
On September 7, he was selected for the 2016 European Baseball Championship.[22]
On February 7, 2017, he was selected for the training camp in the United States.[23] On March 20, 2017, he was selected for the 2017 World Baseball Classic after Didi Gregorius was injured.[24]
