High School/Club:

Brennan was a two year started and letter-winner at Lawrence High School. He scored 12 points, 4 assists, and 5 rebounds per game while hitting 90 percent of his free throws during his senior season. His junior season say him average 9 points, 2 assists, and 2 rebounds while hitting 88 percent of his free throws. Brennan was named All Sunflower League his senior season.