The Brazilian has been linked with Europe's elite clubs but has previously indicated that Barca could be his preferred destination.
However, Rosell says that he has no idea if the 21-year-old will swap his homeland for Catalonia.
"Barcelona are always looking for the best players," Rosell told SIC Noticas. "Besides home-grown players, we look for the best players from outside [Barcelona] that can improve the squad.
"As for Neymar, I don't know when he'll come. He is a Santos player until 2014.
"Neymar, like any other players that are interesting Barcelona scouts, might join the team eventually."
Neymar has scored 17 goals in 28 senior caps for Brazil.