Mirco entered the 2021 season as the Buckeyes starting punter, at the age of 24.[4] In week two of the season, Mirco punted three times, where all three were downed inside the 20 yard line, while two were downed at the one yard line.[5] Mirco finished the 2021 season punting the ball 31 times for 1,310 yards.[6] In week five of the 2022 season, he converted a fake punt where he ran for 22 yards in a win over Rutgers.[7] In week ten, Mirco punted seven times for 352 yards with an average of 50.4 yards, including two punts over 50 yards, and downed a punt inside the five yard line.[8] He finished the 2022 season punting 49 times for 2,223 yards with an average of 45.4 yards per punt,[9] earning honorable mention all-Big Ten Conference honors.[10] Mirco also finished as one of the ten semifinalists for the Ray Guy Award.[11] For the 2023 season, Mirco was named to the Ray Guy Award watchlist.[12]
On December 30, 2023, shortly after playing in the 2023 Cotton Bowl, Mirco announced that he would enter the transfer portal.[13]
Vanderbilt
On January 3, 2024, Mirco announced he would be transferring to Vanderbilt.[14]