A 6’6 righthander from Highlands Ranch, Colorado, Whalen rejoins the Bucks after appearing in 9 games in 2017. He attended Valor Christian High School, lettering three years in baseball. During his sophomore season, he threw 41.0 innings with a 3.00 ERA and 48 strikeouts. He was selected to the Colorado Rockies High School Futures underclassmen team. Whalen earned preseason All-America honorable mention honors during his sophomore season, and then proceeded to help his team to a state semifinals appearance. He began his collegiate career with Wichita State University in 2015, where he redshirted in his initial season. He then transferred to Cisco College for his 2016 season, going 2-1 in 10 appearances and 23.0 innings with a 6.26 ERA. Whalen transferred back to the Shockers in 2017, striking out 4 and allowing 1 earned run in 2.0 innings. Last summer he threw 10.0 frames for the Bucks, racking up 10 strikeouts. In 2018 Whalen transferred to Colorado-Mesa University, where he struck out 2 in 3.2 frames.