Neymar will line up alongside World Player of the Year Lionel Messi in a formidable forward line for the Spanish champions but they probably need to strengthen a defence that was worryingly porous last season.
"Barca can afford all the transfers the technical staff deem necessary, as has always been the case," Toni Freixa, spokesman for the club's board of directors, told a news conference.
"But we cannot of course tell the market how much we are prepared to spend."
The club's 35-year-old captain Carles Puyol has suffered a series of injury problems and Barca's central defensive pairing last season was typically Gerard Pique and Javier Mascherano, a converted midfielder.
Barca romped to a fourth title in five years but conceded 40 goals in 38 matches, 11 more than the previous campaign.
Neymar's Brazil team-mate Thiago Silva told reporters this week that Barca coach Tito Vilanova had tried to coax him to the Catalan capital but the centre-back's club, Paris St-Germain, are reluctant to part with him.
Vilanova has seemed reluctant to heap too much responsibility on Spain Under-21 international Marc Bartra. He had a fine European Championship in Israel last month and could play more of a role next season.
Alex Song, another midfielder, was bought from Arsenal because he can also fill in at centre back but has proved a disappointment.
Daniel Alves and Jordi Alba are fixtures at right and left back respectively and Barca have Martin Montoya and Adriano as cover.
The arrival of Neymar may trigger the exit of David Villa, who has not been the same lethal marksman since breaking his leg at the Club World Cup in late 2011 and will be 32 in December. ($1 = 0.7671 euros)