[1] As a senior, he was the Hawaii Gatorade Baseball Player of the Year after going 7–1 with a 0.97 earned run average (ERA) and 83 strikeouts in 43+1⁄3 innings pitched.

[8] He signed on June 14,[9] forgoing his commitment to Pepperdine, and was assigned to the Arizona League Brewers where he went 0–2 with a 7.13 ERA in 17+2⁄3 innings pitched.

Medeiros spent 2017 with the Carolina Mudcats, pitching to an 8–9 record, a 4.98 ERA, and a 1.31 WHIP in 27 games (18 starts).

On July 26, 2018, Medeiros was traded to the Chicago White Sox (along with Wilber Perez) in exchange for Joakim Soria.

[16] Medeiros made 10 appearances for the Triple-A Salt Lake Bees, but struggled to a 10.80 ERA with 9 strikeouts in 11.2 innings pitched.