source: bleacher's report
According to ESPN Boston's Chris Forsberg (@ESPNForsberg), the league has instituted a new uniform rule, prohibiting players from wearing their headbands upside down or inside out. Players may now only wear them if the NBA and/or team logo is shown right side up, the way it's supposed to. Rondo has worn a sweatband for quite some time now, but he would wear it upside-down for unknown reasons. With the NBA instituting the new rule, he has ditched the headband altogether, starting the Boston's opener against the Miami Heat.