Colorado Rockies The
Colorado Rockies selected Rolison in the first round, with the 22nd overall selection, in the
2018 Major League Baseball draft, and he signed with the Rockies for a $2.9 million
signing bonus. He made his professional debut with the
Grand Junction Rockies of the
Rookie-level Pioneer League and spent the whole season there. In nine starts, he compiled a 0–1 record with a 1.86 ERA and a 0.79 WHIP. Rolison began 2019 with the
Asheville Tourists of the
Single-A South Atlantic League. Rolison was promoted to the
Lancaster JetHawks of the
High-A California League after going 2–1 with a 0.69 ERA and 14 strikeouts in 14 innings with the Tourists. With Lancaster, he was selected to participate in the All-Star Game as a member of the South Division team. Over 22 starts with the JetHawks, Rolison went 6–7 with a 4.87 ERA, striking out 118 over innings. He did not play in a game in 2020 due to the cancellation of the minor league season because of the
COVID-19 pandemic. To begin the 2021 season, Rolison was assigned to the
Hartford Yard Goats of the
Double-A Northeast. After going 2–1 with a 3.07 ERA over three starts, he was promoted to the
Albuquerque Isotopes of the
Triple-A West. On June 14, he was placed on the
injured list after having his
appendix removed. He was expected to return in early August, but broke a bone in his left hand while fielding balls, delaying his return. He was activated later that same month. Over ten starts with the Isotopes, Rolison went 2–2 with a 5.91 ERA and 45 strikeouts over 45 innings. Following the end of the season, Rolison began playing in the
Dominican Professional Baseball League for the
Tigres del Licey. On November 19, 2021, the Rockies selected Rolison's contract and added him to their 40-man roster. He opened the 2022 season on the injured list with a shoulder injury. In June, it was announced that Rolison was scheduled for surgery and would miss the entire season. On March 25, 2023, Rolison was placed on the 60-day injured list to begin the year. After rehabbing with the Single-A
Fresno Grizzlies, Rolison was activated from the injured list on May 29 and optioned to Triple-A Albuquerque. He was placed back on the injured list with an unspecified injury on June 4, and was transferred back to the 60-day injured list on July 14. Following the season on October 20, Rolison was removed from the 40-man roster and sent outright to Triple–A Albuquerque. In 2024, Rolison began pitching primarily out of the
bullpen, splitting the year between the rookie-level
Arizona Complex League Rockies, High-A
Spokane Indians, and Albuquerque. In 29 appearances (5 starts) for the three affiliates, he accumulated a 2–3 record and 4.47 ERA with 35 strikeouts across innings pitched. Rolison began 2025 back with Albuquerque, recording a 3–1 record and 3.72 ERA with 23 strikeouts over his first 12 games. On May 11, 2025, Rolison was selected to the 40-man roster and promoted to the major leagues for the first time. On August 16, Rolison recorded his first career win, tossing a scoreless inning of relief against the
Arizona Diamondbacks. He made 31 appearances for the Rockies during his rookie campaign, but struggled to a 7.02 ERA with 25 strikeouts across innings pitched. On November 18, Rolison was
designated for assignment by Colorado.
Chicago Cubs On November 19, 2025, Rolison was traded to the
Atlanta Braves in exchange for cash. He was designated for assignment by the Braves following the signing of
Robert Suárez on December 11. The next day, Rolison was claimed off waivers by the
Chicago White Sox. He was designated for assignment by Chicago following the signing of
Sean Newcomb on December 23. On January 7, 2026, Rolison was claimed off waivers by the
Chicago Cubs. He was optioned to the Triple-A
Iowa Cubs to begin the regular season. He was called up to the Cubs and made his regular season debut in a 10-4 win over the
Phillies on April 14, throwing one shutout inning. ==Personal life==