Aside from adding Neymar, the Liga champion has been quiet in the transfer market so far, but the Blaugrana are keen to add to their squad before the start of the new season.
The Catalans have so far only secured the services of Neymar from Santos in a deal worth $75 million, but they are keen to add to their squad prior to the close of the summer transfer window.
Barcelona has been linked with a number of center backs in recent months, including Thiago Silva, Mats Hummels, Daniel Agger and David Luiz, but the club has so far refused to comment on any potential transfer targets.
"We want to add one more player to our squad before the end of the transfer window," Rosell told Sport. "However, it's important to acknowledge that you cannot always get the player you want as some clubs simply don't want to sell."
On other player fronts, Barcelona confirmed on Thursday that it has extended Cristian Tello's contract, while the club also says that Alexis Sanchez is not for sale.