Mantineo, a 2017 Montclair State University, joined the Highlanders lacrosse program during the 2017-2018 school year. Helping NJIT in the fall as a volunteer coach, he moved up the ranks in the sprin. Now heading into his fifth season at NJIT in 2022, Mantineo was promoted to lead assistant in Fall 2021.
Mantineo played for Montclair State for four years as a faceoff specialist, appearing in 74 games, and earning a .643 FO%. His 413 career ground balls are the most in Montclair State men's lacrosse history. In his senior year was named to the USILA All-America Team (honorable mention), Second Team All-East by the IMLCA and First-Team All-Skyline Conference. Mantineo set Montclair men's lacrosse single-season marks for faceoff wins (298) and percentage (.708) in 2017. Mantineo also spent a brief stint in the training camp of Major League League Lacrosse's Charlotte Hounds.
