Brosnan joined Stony Brook Baseball as the Assistant Coach and Pitching Coach in September of 2021 and immediately aided the Seawolves' pitching staff.
He helped faciliate Ben Fero's transition from the bullpen to of one of the league's best starters, finishing off his senior season with an 11-strikeout effort against NJIT. In the bullpen, two relievers had outstanding seasons in sophomore Brendan Patterman, who led the team in saves, and Josh O'Neill, who closed the year with a sub-1.00 ERA over the final month. He also led the development of 2022 All-Rookie selection Colton Book into an every-weekend starter.
Prior to Stony Brook, Brosnan was the Assistant Coach/Pitching Coach at Molloy College on Long Island for the past 4 years. While at Molloy, not only was Brosnan the Pitching Coach, he also was the Recruiting Coordinator for the program in charge of evaluating and assessing prospects to recruit to Molloy.
He also as the pitching coach created and planned all skill instruction for their pitching staff, including a winter throwing program and a weighted ball program. Brosnan is a 2015 graduate of Molloy with his Bachelor's Degree, and a 2020 graduate of Molloy with his Master's Degree.
Prior to his employment at Molloy College, he was an Assistant Baseball Coach for 1 year at Nassau Community College on Long Island.
