He spent 2016 with the Clinton LumberKings where was compiled a 7–1 record, 2.13 ERA, and 0.91 WHIP in 17 games (13 starts), and he began 2017 with the Modesto Nuts.

On July 20, 2017, the Mariners traded López, along with Brayan Hernandez, Brandon Miller and Lukas Schiraldi to the Miami Marlins for David Phelps.

López was promoted to the major leagues on June 30, 2018, and he made his MLB debut that same day as the starting pitcher at Marlins Park versus the New York Mets.

[8] He pitched six innings in which he gave up two runs on six hits while walking one and striking out five, earning the win as Miami defeated the Mets 5–2.

[9] In June 2019, López suffered a mild right shoulder strain[10] that led to a two-month stint on the injured list.

[11] López struck out Ehire Adrianza, Freddie Freeman, Ozzie Albies, Austin Riley, Orlando Arcia, Dansby Swanson, Guillermo Heredia, Kevan Smith, and Ian Anderson on 35 pitches during the first, second, and third innings.

[13] On January 13, 2023, López agreed to a one-year, $5.45 million contract with the Marlins, avoiding salary arbitration.

[14] On January 20, 2023, the Marlins traded López, José Salas, and Byron Chourio to the Minnesota Twins for Luis Arráez.

During his time in the Seattle Mariners farm system, Lopez became fluent in four languages: Spanish, English, Portuguese (when conversing with Brazilian teammates) and Italian, though he said he's 'rusty'.