According to Brazil's news outlet, Barcelona must pay a further 3.2 million euros by Wednesday to secure the forward under the agreement.
Barcelona have until this week to exercise an option to sign highly-rated Brazilian teenager Gustavo Maia, according to press reports in the South American country.
The Catalan club paid one million euros ($1.1 million) to acquire the right of first refusal for Maia in March, following the 19-year-old's impressive performances for Sao Paulo's under-20 team.
According to Brazil's Lance news outlet, Barcelona must pay a further 3.2 million euros by Wednesday to secure the forward under the agreement.
It added that Sao Paulo were optimistic the transfer would go ahead.
Former Athletico Paranaense goalkeeper Neto is currently the only other Brazilian in Barcelona's squad following the departure of midfielder Arthur to Juventus.
