Quickly becoming a starting safety, Leonhard was twice named to the First Team All-Big Ten team before his senior year, at which point he was finally put on scholarship. After a stellar final year with the Badgers, Leonhard went undrafted in 2005 and landed with the Bills. There, he was the only undrafted rookie to make Buffalo's roster. Injuries helped him start a handful of games towards the end of his third season, which preceded his signing in Baltimore.