He cites his experience watching his father play in a Southern California baseball league as inspiring him to take up the sport.

After posting a combined 10–3 (W–L) record, with a 2.16 ERA, and 128 strikeouts, he was named the Phillies’ minor league pitcher of the year.

[7] Showing a glimpse of Romero’s enormous promise, on May 10, 2017, he threw eight one-hit innings against the Greenville Drive, in a BlueClaws home victory at FirstEnergy Park.

[11] On August 21, 2020, with the Phillies playing a road game in Atlanta, Romero made his big league debut.

[14] On July 30, 2022, Romero was traded to the St. Louis Cardinals in exchange for infielder Edmundo Sosa.

[15] Romero pitched in 15 games for St. Louis down the stretch, recording a 3.77 ERA with 16 strikeouts in 14.1 innings of work.