St. Clair most recently coached at the University of Illinois at Chicago in 2016, serving as the program's hitting coach and was part of the program's second-consecutive Horizon League regular-season championship.
Prior to UIC, St. Clair's resume also includes a lengthy four-year stint at Memphis and played in the NPF for the Akron Racers in 2011.
A 2010 Michigan grad, St. Clair was part of three Big Ten championship-winning squads and twice earned All-Big Ten honors as a Wolverine. She helped lead the program to an appearance in the 2009 Women's College World Series.
She joins a Rutgers program that is coming off a 2016 season that saw them post an overall 24-33 record, including an 8-15 mark in conference play. The Scarlet Knights won outright just three conference series' in 2016, and were themselves swept in four. They closed the campaign with a shutout loss to Ohio State in the B1G conference tournament.