 He enlisted in the U.S. Army, serving two years in the military police and finished his undergraduate degree at Rutgers University.While there, he captained the football team and played center on the school's first undefeated football team, making all seven All-American teams in 1961, while leading the team to a 17-1 record in his two seasons and becoming a Henry Rutgers Scholar along the way.Kroll was a 1962 player for the American Football League's New York Titans (later the Jets), playing center and offensive tackle.