Holmes was officially signed by the Dodgers on June 17, 2014 for $2.5 million.[9] The Dodgers assigned him to the
Arizona League Dodgers to begin his professional career. He was 1–2 with a 3.00 ERA in seven appearances for them, before he was promoted, on August 14, 2014, to the
Ogden Raptors.[10] In four starts for Ogden, he was 1-1 with a 4.91 ERA.[11] Holmes was assigned to the
Great Lakes Loons to start the 2015 season.[12] He was selected to the mid-season All-Star team.[13] He finished the season with a 6–4 record and 3.14 ERA in 24 starts.[14] Holmes was promoted to the
Rancho Cucamonga Quakes to start the 2016 season.[15]
Oakland Athletics
On August 1, 2016, the Dodgers traded Holmes,
Jharel Cotton, and
Frankie Montas to the
Oakland Athletics in exchange for
Rich Hill and
Josh Reddick.[16] Oakland assigned Holmes to the
Stockton Ports, where he finished the season; in 26 total games (23 starts) between Rancho Cucamonga and Stockton, he posted a combined 11–7 record and 4.63 ERA. Holmes spent 2017 with the
Midland RockHounds, pitching to an 11–12 record and 4.49 ERA with 150 strikeouts in 148+1⁄3 innings pitched.[17]
The Athletics added Holmes to their
40-man roster after the 2018 season.[18] Holmes missed over a month during the year with shoulder soreness, and split the 2019 season between Midland and the
Las Vegas Aviators, going a combined 6–5 with a 3.23 ERA and 81 strikeouts over 86+1⁄3 innings.[19][20] Holmes did not play in a game in 2020 due to the cancellation of the minor league season because of the
COVID-19 pandemic.[21] In 2021, Holmes played for Triple-A Las Vegas, and pitched to a 8.01 ERA in 36 appearances for the team.[22] On April 1, 2022, the Athletics sent Holmes outright to Las Vegas, removing him from their 40-man roster.[23] He was released on July 28, 2022.
Atlanta Braves
On August 13, 2022, Holmes signed a minor league deal with the
Atlanta Braves organization. He made three appearances split between the rookie–level
Florida Complex League Braves and High–A
Rome Braves to conclude the year.
Holmes spent the 2023 season with the Triple–A
Gwinnett Stripers, appearing in 50 games and registering a 7–3 record and 3.54 ERA with 74 strikeouts and 13
saves across 61.0 innings of work. He elected free agency following the season on November 6.[24]
On November 22, 2023, Holmes re–signed with the Braves on a new minor league contract.[25]