BSC Old Boys
He was promoted to first team in 2005–06 season and also played for Basel II at 1. Liga that season. Kuzmanović scored his first goals for Basel in the second round of the Swiss Cup, in a 6–1 win over BSC Old Boys. Kuzmanović scored two more goals later in the season. Following his good performance, he was reported by UEFA as one of the most interesting young players in Europe and was awarded with the Swiss Golden Player Award for season 2006.