Morrissey walked-on to Pittsburgh's football team and redshirted his true freshman season. He was named the Panthers' starting center and awarded a scholarship going into his redshirt freshman season and started all 12 of the team's games.[1] Morrissey started the first 11 games of his redshirt sophomore season before suffering a season-ending injury and was named third-team All-Atlantic Coast Conference (ACC).[3] He was named first-team All-ACC as a redshirt junior.[4] As a redshirt senior, Morrissey started all 11 of Pittsburgh's games, including one at right guard after an injuries to that position, and was named second-team All-ACC and was awarded the Burlsworth Trophy as the best player in Division I football who began his college career as a walk-on.[5][6]
Morrissey was selected by the Las Vegas Raiders in the seventh round, 230th overall, of the 2021 NFL draft.[10] He signed his four-year rookie contract with Las Vegas on May 17.[11] He was waived on August 31, 2021 and re-signed to the practice squad the next day.[12][13]
Houston Texans
Morrissey was signed off the Raiders' practice squad by the Houston Texans on October 19, 2021.[14] He made his NFL debut on November 7, 2021, as the team's starting center in a 9–17 loss to the Miami Dolphins.[15]
On August 30, 2022, Morrissey was waived by the Texans and signed to the practice squad the next day.[16][17] He was promoted to the active roster on September 21.[18]
On August 29, 2023, Morrissey was waived by the Texans and re-signed to the practice squad.[19][20] He was not signed to a reserve/future contract after the season and thus became a free agent when his practice squad contract expired.[21]
New York Giants
On January 23, 2024, Morrissey signed a reserve/future contract with the New York Giants.[22] He was waived on August 27, and re-signed to the practice squad.[23][24]