Keisel attended Gunnison Valley High School in Utah. He was a two-time All-State selection and was ranked the No. 1 prospect in Utah by Prep Baseball Report. He chose to join BYU following his high school career.
As a freshman with BYU, Keisel made 19 appearances including 9 starts. He had a 4.27 ERA and struck out 58 batters in 46.1 innings pitched. He entered the transfer portal following this freshman campaign.
Keisel transferred to Oklahoma State ahead of the 2023 season. As a sophomore with the Cowboys, Keisel made 9 appearances including 4 starts. He struggled a bit, posting a 7.85 ERA with 34 K's and 19 walks in 18.1 innings pitched.
This year is Keisel's junior season. He aims to return to form and reclaim the attention he gained during his high school and college freshman seasons.