He has previously played in Major League Baseball (MLB) for the Kansas City Royals, Tampa Bay Rays, and Baltimore Orioles.

[6][7] On November 12, 2015, the Angels traded Ellis, Sean Newcomb, Erick Aybar and cash to the Atlanta Braves in exchange for Andrelton Simmons and José Briceño.

On December 1, 2016, the Braves traded Ellis, John Gant, and Luke Dykstra to the St. Louis Cardinals in exchange for Jaime García.

[13] Ellis spent 2017 with both the Double-A Springfield Cardinals and Triple- A Memphis Redbirds, posting a combined 7–12 record with a 5.29 ERA in 30 games (22 starts) between both teams.

[15] On December 13, 2018, the Texas Rangers selected Ellis in the 2018 Rule 5 draft and traded him to the Kansas City Royals.

[17] He made his major league debut on March 31, 2019, versus the Chicago White Sox, recording one scoreless inning of relief.

[32] On April 10, 2024, Ellis signed with the Long Island Ducks of the Atlantic League of Professional Baseball.

[35] On August 1, 2024, Ellis signed with the Long Island Ducks of the Atlantic League of Professional Baseball.