Baseball America ranked Melville as the best high school player available in the 2008 Major League Baseball draft. Because of the commitment to UNC, Melville fell out of the first round in the draft. The Kansas City Royals selected him in the fourth round, with the 115th overall selection, and signed him to a contract with a $1.25 million signing bonus.[4]
Melville began his professional career with the Burlington Bees of the Single–AMidwest League in 2009, pitching to a 7–7 win–loss record and a 3.79 ERA. He was promoted to the Wilmington Blue Rocks of the High–ACarolina League in 2010, where he struggled, pitching to a 2–12 win–loss record and a 4.97 ERA. He returned to Wilmington in 2011, and compiled an 11–10 record with a 4.32 ERA.[5] Melville required Tommy John surgery in 2012. In 2014, Melville pitched for the Northwest Arkansas Naturals of the Double–ATexas League, but struggled with a 2–11 win–loss record, a 5.50 ERA, while allowing 68 walks in 129+1⁄3 innings.[6]
On April 8, the Reds announced Melville would start in the series finale against the Pittsburgh Pirates, in place of Anthony DeSclafani, on April 10. The start marked Melville's MLB debut.[10] He threw 4 innings, giving up 1 run in a no-decision vs. Pittsburgh. Melville was designated for assignment by the Reds on April 22. After clearing waivers on April 24, he spent the remainder of the year with Louisville and the Double–A Pensacola Blue Wahoos, logging a combined 4.85 ERA with 59 strikeouts across 38 appearances out of the bullpen. Melville elected free agency following the season on November 7.[11]
On August 26, 2017, Melville was claimed off waivers by the San Diego Padres.[13] He made only two appearances for the Padres, allowing three runs (two earned) on three hits with three strikeouts. On November 6, Melville was removed from the 40–man roster and sent outright to the Triple–A El Paso Chihuahuas.[14] However, Melville rejected the assignment and subsequently elected free agency the following day.
Baltimore Orioles
On December 22, 2017, and signed a minor league contract with the Baltimore Orioles organization.[15] He spent the entire season with the Triple–A Norfolk Tides, making 40 appearances and registering a 9–6 record and 5.33 ERA with 82 strikeouts and 4 saves across 104+2⁄3 innings pitched.[16] Melville elected free agency following the season on November 2, 2018.[17]
On May 3, 2019, Melville's contract was purchased by the Colorado Rockies, and he was assigned to the Triple-AAlbuquerque Isotopes.[19] On August 21, the Rockies selected Melville's contract and promoted him to the major leagues as an emergency starter.[20] In his Rockies debut against the Arizona Diamondbacks, Melville pitched 7 innings and allowed only 1 run on 2 hits as the Rockies won 7–2, giving Melville his first major league win. 5 days later, Melville made his debut at Coors Field and had another impressive performance against the Atlanta Braves, pitching 5 shutout innings and striking out 6 as the Rockies went on to defeat the Braves 3–1. Melville's ERA of 0.75 is the 3rd lowest ERA posted by a Rockies pitcher through his first two starts with the club. On October 30, Melville was removed from the 40–man roster and sent outright to Triple–A Albuquerque.[21]
Melville re-signed with the Rockies on a minor league contract on February 5, 2020. He did not play in a game for the organization in 2020 due to the cancellation of the minor league season because of the COVID-19 pandemic.[22] Melville was released by the Rockies organization on May 18.
Uni-President Lions
On July 12, 2020, Melville signed with the Uni-President Lions of the Chinese Professional Baseball League.[23] He re-signed with the team for the 2021 season.[24] On April 2, 2021, Melville pitched a no-hitter against Wei Chuan Dragons becoming the 10th player to do so in Chinese Professional Baseball League history. He also set the record of most pitches thrown in a no-hitter in the league, with 142 pitches.[25] For the season, Melville posted a 8–7 record with a 3.74 ERA and 84 strikeouts over 122.2 innings. He was not re-signed for the 2022 season and became a free agent.
Wei Chuan Dragons
Melville took the 2022 season off as he dealt with elbow inflammation. He received platelet-rich plasma treatment for the injury. On February 8, 2023, Melville signed with the Wei Chuan Dragons of the Chinese Professional Baseball League.[26] Pitching in 3 games, he registered a 9.24 ERA and 1.50 WHIP across 12+2⁄3 innings of work. On May 27, it was announced that Melville would miss 3–4 months after suffering injuries in his right elbow and tendon, and he was subsequently released by the team.[27]