Iniesta has been holding contract talks with Barca but has yet to reach a conclusion on a new deal.
However, Rosell insists that the club will come to an agreement with the World Cup winner soon.
"Iniesta will end his career at the club," Rosell told Cadena SER. "If I had to bet on his future, I would do so on that. We believe he should be on the second-highest salary behind Lionel Messi."
Barca are currently top of La Liga, having won all eight of their games this season.