Coming out of high school, Whitmer was rated as a four-star recruit and committed to play college football for the Illinois Fighting Illini.
[3] In his lone season as the starter at Butler, he completed 180 of his 316 passing attempts for 3,022 yards with 25 touchdowns and 14 interceptions.
[8] In 2019, Whitmer got his first career coaching job, joining the Ohio State Buckeyes as a graduate assistant.
[11] On February 2, 2024, he was hired by the Atlanta Falcons to be the team's pass game specialist for the upcoming season.
[12] Ahead of the 2025 season, Whitmer was hired by the Indiana Hoosiers to serve as the team's co-offensive coordinator and quarterbacks coach following the departure of Tino Sunseri.