As a freshman in 2020, Arnold hauled in six receptions for 45 yards.[4] He caught three passes for 33 yards and two touchdown in the 2021 season opener, helping Kansas beat South Dakota 17–14.[5][6] Arnold finished the season with 27 receptions for 316 yards and three touchdowns.[7] In week four of the 2022 season, he made four receptions for 84 yards and a touchdown in a 35–27 win over Duke.[8] In week seven, Arnold brought in five receptions for 113 yards and two touchdowns as the Jayhawks fell 52–42 against Oklahoma.[9][10] In the 2022 Liberty Bowl, he made eight catches for 119 yards, but the Jayhawks lost in triple overtime versus Arkansas.[11] Arnold finished the 2022 season with 44 receptions for 716 yards and four touchdowns.[12] Ahead of the 2023 season, Arnold was named to the Earl Campbell Tyler Rose Award watch list.[13]