Ríos was born in Caguas, Puerto Rico. He was Philadelphia's 12th-round selection in the 2011 Major League Baseball draft, out of Doctora Conchita Cuevas High School in Gurabo, Puerto Rico. He made his professional debut later that year, with the Gulf Coast League Phillies where he pitched to a 0-1 record, and 8.47 ERA, in 11.1 innings. Ríos returned to the GCL in, where he was 2-2, with a 6.60 ERA, in 30 innings pitched. In, he played for the Williamsport Crosscutters, where he was 5-3, with a 3.59 ERA, in 15 games. The season found Ríos pitching for the Lakewood BlueClaws, where he compiled a 6-2 record, and 3.69 ERA, in 102.1 innings pitched. He spent with the Clearwater Threshers, where he was 6-5, with a 2.75 ERA, in 26 games. The next year,, again found him with Clearwater, the GCL Phillies, and the Reading Fightin Phils, where he was a combined 5-4, with a 5.74 ERA, in 37 games. Ríos began with Reading, then finished that year with the Phillies’ AAAfarm team, the Lehigh Valley IronPigs; over 37 total minor league appearances that year, he was 1-3, with a 1.92 ERA, with 64 strikeouts, in 56.1 innings.
Philadelphia Phillies
Ríos was called up to the majors for the first time on August 22, 2017. He made his MLB debut that same day, pitching 1 innings of no-hit baseball against the Miami Marlins. On September 27, Ríos earned his first career win, pitching in relief against the Washington Nationals. He spent the rest of the season with the Phillies and in 13 games, he was 1–0, with a 4.41 ERA. For the 2018 Phillies, Ríos was 3–2, with a 6.75 ERA, in 36 innings pitched. With Lehigh Valley, he was 0-0 with a 3.97 ERA in 22.2 innings in which he walked 17 batters and struck out 26 batters. In 2019 with the Phillies, he went 0–0 with a 13.50 ERA in 2.2 innings over 4 games. With the Class AAA Lehigh Valley IronPigs, he was 1-3 with a 7.41 ERA in 34 innings in which he walked 22 batters and struck out 37 batters. He was designated for assignment on July 29, 2019.
Pittsburgh Pirates
On August 3, 2019, Ríos was claimed off waivers by the Pittsburgh Pirates. Pitching for the Indianapolis Indians in 2019 he was 0-0 with one save and a 2.35 ERA in 9 games. Pitching for the Pirates he was 1-0 with a 5.23 ERA in 10 games.
