Neymar denies wrongdoing over 2013 Barcelona transfer
"My father has always been in charge" of contract negotiations, the 30-year-old told the Barcelona court hearing the case.
"I sign what he tells me to."
The trial is the culmination of a years-long legal saga over his 2013 transfer, with Neymar one of nine defendants in the dock on corruption-related charges, among them his parents and their N&N company, which manages his affairs.
The proceedings began barely a month before the November 20 start of the World Cup, at which Neymar is expected to play a key role for Brazil.
Dressed in a dark suit and white shirt, the footballer said he didn't remember if he participated in talks leading to a pre-contract deal with Barcelona in 2011 ahead of his transfer two years later from the Brazilian club Santos.
He said he had always dreamed of playing for Barca so he had prioritised their offer over that of other clubs, such as Real Madrid.
"Neymar never takes part in the negotiations," his father Neymar Da Silva Santos told the court.
If convicted, prosecutors have called for a two-year jail term and a 10-million-euro (£8.7 million) fine for the footballer who since 2017 has played for Paris Saint-Germain (PSG).
Prison terms of two years or less are never enforced in Spain for a first-time offender.
Complicity to defraud
Investigators began probing the transfer after a 2015 complaint filed by DIS, a Brazilian company that owned 40 percent of the player's sporting rights when he was at Santos.
The firm claims that Neymar, Barcelona and the Brazilian club colluded to mask the true cost of his transfer thereby defrauding it of its legitimate financial interests.
Barca said the transfer was valued at 57.1 million euros, with 40 million euros paid to N&N and 17.1 million to Santos, of which 6.8 million was given to DIS.
Spanish prosecutors believe the actual value was at least 83 million euros.
Neymar had originally been due to testify later in the month but the court agreed to bring forward his appearance in order to avoid a clash with his busy PSG schedule.
After testifying, the court agreed Neymar and his family could return to Paris immediately and take part in the trial's conclusion, expected on October 31, by video conference.
The PSG forward, who scored the only goal of their Ligue 1 match against Marseille on Sunday night, had spent two hours in court on Monday for the opening of the trial but was excused by the judge to allow him time to rest.
'Not my responsibility'
DIS also claims financial harm from the 2011 pre-contract agreement with Barca saying it had impeded other clubs from making offers and affected the value of the transfer fee.
But Neymar Sr told the court the talks had been authorised by the Brazilian club at the time and that "it was Santos' responsibility" to inform DIS, and not his.
Other defendants in the dock include two former Barca presidents, Sandro Rosell and Josep Maria Bartomeu, and ex-Santos boss Odilio Rodrigues Filho.
DIS is seeking to recover 35 million euros (£30.5 million).
Neymar's lawyers insist their client is innocent, saying the 40-million-euro (£34 million) payment from Barca was a "legal signing bonus which is normal in the football transfer market".
The footballer is having one of his best seasons since he joined PSG.
His Sunday night goal against Marseille was his ninth league goal of the season, and he has seven assists in 11 Ligue 1 matches.
Neymar is expected to play a key role for Brazil at the World Cup in Qatar, as the South American giants seek to win the trophy for the first time since 2002, and the sixth in total.
He will lead the Selecao into their Group G opener against Serbia on November 24.
