Rosell feels the Catalan giants have a responsibility to look after Messi's interests, although he admits talks have yet to be scheduled.
"It finishes in 2016, but it would be irresponsible to not improve his contract," Rosell told Catalunya Radio.
"You have to think about such things. Right now there is nothing scheduled, but this is a machine that is constantly in motion and things can change at any moment."
Rosell added: "The coaching staff think about next Sunday, we look further down the line and take the more distant future into consideration.
"Work has to start now on the contract that will take effect from 2016."