Will Brennan and the KC Barnstormers (KS) competed at Cooperstown Dreams Park during Tournament 8 in 2010, reaching the Elite 8.

Will graduated from Blue Valley High School (Overland Park, KS) where he excelled on the diamond. The outfielder’s accolades include: 2016 6A Kansas Co-Player of the Year, 2015-16 First Team All-State (OF), 2015-16 Eastern Kansas League First Team, and 2014 Eastern Kansas League Honorable Mention (LHP). Will participated in 2016 Kansas All-Star Game and was member of 2014 state champion team.

After high school Will was at Kansas State University (Manhattan, KS), majoring in Kinesiology and playing baseball. Throughout three collegiate seasons, he earned All-Big 12 First Team (2018), Collegiate Baseball Freshman All-American (2017), NCBWA Second Team Freshman All-American (2017), Second Team All-Big 12 (2017), All-Big 12 Freshman Team (2017), Academic All-Big 12 First Team (2019), Academic All-Big 12 First Team (2018), Academic All-Big 12 Rookie Team (2017), Big 12 Player of the Week (3/12/18), Big 12 Newcomer of the Week (4/10/17), Big 12 Newcomer of the Week (4/24/17), and Preseason All-Big 12 Team (2019). Will also excelled in the classroom earning Big 12 Commissioner's Honor Roll honors five times.

Will shifted to professional baseball when he was drafted by the Cleveland Guardians during the 2019 Major League baseball draft. He made his Major League debut on September 21, 2022. Will and the Guardians clinched the 2024 American League Central division.