As a freshman in 2017, Rolison began the season in the bullpen before moving into the starting rotation. In 19 games (ten starts), he compiled a 6-3 record and a 3.06 ERA, holding opposing batters to a .242 average, earning him a spot on the SEC All-Freshman team along with freshman All-American honors.[4][5][6][7] After his freshman season, he played for the Orleans Firebirds of the Cape Cod Baseball League where he went 4-0 with a 1.92 ERA and was named a league all-star.[8][9][10] Rolison was named a First Team Preseason All-American prior to his sophomore season.[11] As a sophomore in 2018, Rolison posted a 10-4 record over 17 appearances (16 starts) with a 3.70 ERA and 120 strikeouts.[12]
Rolison began 2019 with the Asheville Tourists of the Single-ASouth Atlantic League.[17] Rolison was promoted to the Lancaster JetHawks of the High-ACalifornia League after going 2-1 with a 0.69 ERA and 14 strikeouts in 142⁄3 innings with the Tourists.[18] With Lancaster, he was selected to participate in the All-Star Game as a member of the South Division team.[19] Over 22 starts with the JetHawks, Rolison went 6-7 with a 4.87 ERA, striking out 118 over 116+1⁄3 innings.[20] He did not play in a game in 2020 due to the cancellation of the minor league season because of the COVID-19 pandemic.[21] To begin the 2021 season, Rolison was assigned to the Hartford Yard Goats of the Double-A Northeast.[22] After going 2-1 with a 3.07 ERA over three starts, he was promoted to the Albuquerque Isotopes of the Triple-A West.[23] On June 14, he was placed on the injured list after having his appendix removed.[24] He was expected to return in early August, but broke a bone in his left hand while fielding balls, delaying his return.[25] He was activated later that same month.[26] Over ten starts with the Isotopes, Rolison went 2-2 with a 5.91 ERA and 45 strikeouts over 452⁄3 innings.[27] Following the end of the season, Rolison began playing in the Dominican Professional Baseball League for the Tigres del Licey.[28]
On November 19, 2021, the Rockies selected Rolison's contract and added him to their 40-man roster.[29] He opened the 2022 season on the injured list with a shoulder injury.[30] In June, it was announced that Rolison was scheduled for surgery and would miss the entire season.[31][32] On March 25, 2023, Rolison was placed on the 60-day injured list to begin the year.[33] After rehabbing with the Single-A Fresno Grizzlies, Rolison was activated from the injured list on May 29 and optioned to Triple-A Albuquerque.[34] He was placed back on the injured list with an unspecified injury on June 4,[35] and was transferred back to the 60-day injured list on July 14.[36] Following the season on October 20, Rolison was removed from the 40–man roster and sent outright to Triple–A Albuquerque.[37]
Personal life
The same night that Rolison was selected by the Rockies in the draft, controversy emerged after a tweet by him from 2012 resurfaced in which he wrote “Well we have one hope left … if someone shoots him during his speech,” regarding the 2012 United States presidential election. He later apologized, saying “I had no idea what I was talking about, and it was immature of me to post something like that.”[38][39]