This season, he made an exception for a pair of pint-sized sophomore guards — Darius Branch and Kewan Smith — known throughout the small South Side all-boys Catholic school as "Peanut Butter and Jelly."
"Can't have one without the other," Cannon said.
"It's because of the bond we have with each other," Smith, of Englewood, said of the names.
That closeness has helped Leo (15-13) reach Friday's IHSA Class 2A Robeson Sectional final against Hales Franciscan. Their on-court impact was on full display during Tuesday's 74-67 sectional semifinal victory over Carver Military Academy, in which Branch scored 28 points, including 22 in the second half, and Smith dished out nine assists.
Branch, of Beverly, and Smith have known each other since playing on the same Chicago Park District Small Fry basketball team as 11-year-olds. They battled each other several times as point guards when Branch attended Sutherland Elementary and Smith went to St. Margaret of Scotland school.
They've had to fuse their talents at Leo, with the 5-foot-8 Branch becoming more of a scorer and 5-foot-6 Smith the playmaker. Branch is the third-leading scorer in the Catholic League with an 18 points-per-game average, while Smith averages a conference-best eight assists per game.
Cannon, a Leo alum who lives in Chatham and who also teaches government history at the school, feels confident letting either player handle the ball.
"One thing I love about them, and I've been coaching for a while, is that they're both on the same page for what we need," Cannon said. "And the one thing both of them do well is they don't get down on their teammates and they understand what it takes to be a leader."
That's been a necessity as Leo has only three seniors on its 14-boy roster, and the Lions' starting lineup consists of four sophomores and a junior. Cannon developed a motion offense to make use of his guards' speed, but also to reduce the impact of their lack of height.
"Everybody else is tall," Cannon said. "They're real small, and we can't do a lot of things we could do before, so we have to take advantage of their assets."
Leo won a state championship in 2004, Cannon's first year as head coach. He's been showing this season's squad videotapes from that year to show the Lions what it takes to claim the ultimate crown.
Branch said the clips have been inspirational and noted he's not surprised the Lions are a win away from a sectional trophy.
"By the way we've been practicing, it's been showing in the games," Branch said. "I'm really excited for Friday."