Tampa Bay Rays Romero represented the Rays at the 2012
All-Star Futures Game. He was added to the Rays' 40-man roster on November 20, 2012. Romero was called up to start against the
Baltimore Orioles on September 22, 2013. After spending the entirety of the
2014 season in the minor leagues, Romero returned to major league action in the
2015 season as a reliever, pitching 30 innings for the Rays on the year. Starting the
2016 season, Romero retired 17 consecutive batters across relief appearances to set a franchise record for the Rays. Romero notched his first career save on August 25, 2016, striking out slugger
David Ortiz to seal a Rays victory over the division rival
Boston Red Sox. In total, Romero pitched to a 5.27 ERA over innings with the Rays across three seasons, exhibiting a high walk rate of about five batters per nine innings.
Washington Nationals The Rays traded Romero to the
Washington Nationals for minor league pitcher Jeffrey Rosa on February 7, 2017. Romero pitched for the
Dominican Republic national baseball team in the
2017 World Baseball Classic, earning the win in a March 12 game against
Colombia with a scoreless inning of relief. With the Nationals, Romero quickly became a key cog in manager
Dusty Baker's bullpen as it struggled to find its footing over the first half of the season, going through three closers before Baker decided to handle the ninth inning by committee. While Romero continued to walk batters at an above-average rate, as he had with Tampa Bay, his strikeout rate climbed and his earned run average declined relative to what it had been with the Rays. He was frequently deployed to handle the eighth and even the ninth inning. Romero began the
2018 season on the Nationals′ roster, but in two appearances posted a 13.50 ERA in two innings of work. The Nationals designated him for assignment on April 7, 2018.
Pittsburgh Pirates On April 14, 2018, the
Pittsburgh Pirates claimed Romero off waivers. He appeared in two games for the Pirates, hitting a double in his first at-bat, but in the four innings he pitched he gave up five runs, three of them unearned, on seven hits, giving him an ERA with Pittsburgh of 7.50. In order to make room on their roster for the major-league debut of pitching prospect
Nick Kingham, the Pirates initially decided to designate Romero for assignment on April 29, but within hours changed their minds after Romero and his agent informed them that Romero had injured his shoulder while pitching on April 25. The Pirates instead opted to place him on the 10-day
disabled list. He was designated for assignment on July 2.
Kansas City Royals The
Kansas City Royals claimed Romero off waivers on July 5, 2018. On July 21, 2018, he was designated for assignment. On July 26, 2018, Romero elected to become a free agent.
Chunichi Dragons On December 3, 2018, it was announced that Romero had signed with the
Chunichi Dragons in the
NPB's Central League. On April 4, 2019, Romero made his NPB debut. After the season, he re-signed with Dragons. On December 2, 2020, he became a free agent.
Los Angeles Dodgers On January 14, 2021, Romero signed a minor league contract with the
Los Angeles Dodgers organization that included an invitation to major league Spring Training. He was released on April 4, 2021.
Chiba Lotte Marines On August 10, 2021, Romero signed with the
Chiba Lotte Marines of
Nippon Professional Baseball. He made 4 appearances for the team down the stretch, recording a 1.54 ERA with 20 strikeouts. Romero made 20 appearances for Lotte during the 2022 season, compiling an 8–9 record and 3.36 ERA with 77 strikeouts across innings pitched. He became a free agent following the season.
SSG Landers On December 12, 2022, Romero signed with the
SSG Landers of the
KBO League. He began the 2023 season on the injured list with a shoulder injury, and did not appear in a game for the team. On May 3, 2023, Romero was released by the Landers following the signing of
Roenis Elías.
San Francisco Giants On December 21, 2024, Romero signed a minor league contract with the
San Francisco Giants. He did not make an appearance for the organization before he was released on May 9, 2025.
Toros de Tijuana On February 3, 2026, Romero signed with the
Toros de Tijuana of the
Mexican League. ==Pitching style==