The former Portugal international said recruitment plans include targeting players like Marcus Rashford and Luis Diaz, while also focusing on securing the futures of their current squad members.
"(Barcelona will) not sell our best players (and) can grow with many of the same players," Deco told BBC.
"(It will be) two, three or four signings, (without recruiting) like crazy."
However, he declined to reveal much when asked about reported targets Rashford and Diaz, out of respect for Manchester United and Liverpool respectively.
"They are good but have contracts in their clubs, so we won't speak because it's not fair. But when you decide to go to the market, for sure, we find some names. In my opinion, we don't need to bring many players.
"When I speak with the agents of the players, everyone wants to come or stay. So this is important. The image of the club is still good. We are proud because Barcelona is still such a big club, and the way we are playing football makes players want to come."