[3][4] As a freshman in 2012, Freeland had a 4–5 win–loss record with a 4.55 earned run average (ERA) and 70 strikeouts in 91 innings across 14 games started.

[9] Freeland debuted professionally that summer with the Grand Junction Rockies and was promoted in August to the Asheville Tourists.

[10] Freeland did not start pitching in 2015 in July, due to shoulder fatigue and surgery to remove bone chips in his elbow.

After the regular season, Freeland started six games for the Salt River Rafters of the Arizona Fall League, with a 2.84 ERA and just 13 strikeouts in 26+1⁄3 innings.

In 2016, Freeland began the season with the Hartford Yard Goats, and was promoted to the Albuquerque Isotopes in June.

[12] Freeland made his major league debut with the Rockies on April 7, 2017, against the Los Angeles Dodgers and earned his first MLB win.

[14] It was the first time in 51 years that a starting pitcher made his MLB debut in his team's home opener in the state where he was born.

[14] Freeland hit his first major league home run on May 21, off Cincinnati Reds pitcher Bronson Arroyo.

[15] On July 9, Freeland took a no-hitter into the 9th inning against the Chicago White Sox before allowing a one-out a single to Melky Cabrera.

He finished the season with an 11–11 record and 4.10 ERA in 156 innings, tying for the team lead in wins and hit batsmen with fellow rookie Germán Márquez.

[19] Unlike most pitchers, Freeland excelled at the hitter-friendly Coors Field, setting the single-season Rockies record for home ERA at 2.40.

[20] He pitched 202+1⁄3 innings in 33 starts, striking out 173 batters against 70 walks and 182 hits and holding opponents to a .240 batting average.

While it was the most losses he suffered in a single season, he led the depleted Rockies rotation in ERA, innings pitched, starts, strikeouts, and home runs and hits allowed.

[39] Freeland was the Rockies' Opening Day starter for the third time in his career to begin 2024 but allowed 10 runs while getting only 8 outs in a blowout loss to the reigning National League champion Arizona Diamondbacks.

[40] He struggled to an 0–3 record and 13.21 ERA across his four starts, after which the Rockies placed him on the injured list with a left elbow strain on April 19.