An impact player after two seasons without competition following Tommy John surgery just after his junior year of high school and a redshirt freshman season at Michigan, Brosnahan was both an All-Big Ten Freshman Team and All-Big Ten Tournament Team selection last spring.
He followed up that impressive campaign with a somewhat rocky start to his sophomore season this spring, beginning just 1-7 with a 7.41 ERA in 11 appearances (10 starts). In 51 innings, he allowed 26 walks and 69 hits to go along with 27 strikeouts.
As a redshirt freshman, Brosnahan went 5-4 with a 4.38 ERA for the Wolverines, striking out 61 against 37 walks over 72 innings. In the Big Ten Tournament semifinal against Minnesota, he struck out five over 6.1 innings and allowed just five hits and one run but did not factor in the decision.
At Ann Arbor Pioneer High School in Michigan, Brosnahan had a stellar junior season prior to the aforementioned Tommy John surgery that wiped out his senior year. He earned All-Southeast Conference, All-District, All-Region and Second Team All-State honors.
His father, Robert, played hockey at Eastern Michigan University.
Brosnahan is undecided on his major at Michigan.