Mager joined women's lacrosse as an assistant coach for the Nittany Lions, focusing on defense and goalkeepers, in July 2025
Mager arrives at Penn State following two seasons as the first ever head coach at Rider University. Under his guidance, the Broncs posted a combined 16-19 record in the program’s first two seasons, including wins in each of the program's first four games. In his two seasons, he developed six all conference honorees, and has an athlete named to the IWLCA Senior All-Star Game. In 2025, he guided the Broncs to its first ever conference tournament appearance and win.
Before Rider, Mager coached at FDU-Florham where he produced a 34-7 record during his three seasons with the Devils. In just his second season, his team produced a perfect 16-0 record entering the NCAA Division III Tournament. Following the 2021 season, Mager was named MAC Freedom Coach of the Year and IWLCA Boardwalk Region Coach of the Year with a pair of his athletes earned All-America honors following the season. In 2022, following a 16-3 season, he saw another of his athletes earn All-America honors, with three claiming US Lacrosse Magazine All-America honors.
Prior to his time at FDU, Mager was the head coach as Morristown High School for nine seasons, where he accrued 103 wins, including the Morris County Championship in 2018. That team finished the year ranked No. 8 in the state and in the top 125 nationally. During his time at Morristown, he saw 26 of his players continue their playing careers at the collegiate level, including 12 at Division I programs.
A lacrosse player himself, Mager was a member of the FDU-Florham men's lacrosse team where he played goalie and midfielder for the Devils. During his time with the team, he was named the Andrew Helgeson Memorial Award winner, which is awarded to the player with the most dedication and commitment to the team.