In 36 appearances in 2023 with South Bend, the Double–A Tennessee Smokies and Triple–A Iowa Cubs, Little accumulated a 5–2 record and 2.12 ERA with 105 strikeouts in 63+2⁄3 innings pitched. On September 6, 2023, Little was selected to the 40-man roster and promoted to the major leagues for the first time.[4] Upon making the majors, the 6'8" Little tied the record with Chris Volstad from the 2012 season for being the tallest starting pitcher in Chicago Cubs history. In the 2023 season he pitched in seven games, allowing no runs and five hits over 6 2/3 innings.[5]
Little was named a part of the Cubs' 2024 opening-day bullpen before the season began.[6] On April 3, 2024, Little made his first start, throwing one strikeout with no earned runs in one inning a win against the Colorado Rockies.[7][8] In 30 appearances for Chicago, he compiled a 3.46 ERA with 28 strikeouts across 26 innings pitched. Little was placed on the injured list with a left shoulder strain on July 13.[9] He was transferred to the 60–day injured list on July 22, with what was described as a "likely" season–ending lat strain.[10]