Newcastle football legend Alan Shearer has launched a £9 million High Court damages claim which is driven by "greed and ego", according to a financial adviser.
The 46-year-old former England striker says he was given "negligent" financial advice.
He has sued a financial adviser, Kevin Neal, and pension specialist Suffolk Life.
A judge began overseeing a trial at the High Court in London on Wednesday.
Mr Justice Leggatt is due to hear evidence from Shearer, now a Match Of The Day TV pundit, on Thursday.
Shearer says Mr Neal was "careless" and "dishonest" and he says Suffolk Life breached fiduciary and regulatory duties.
But Mr Neal and Suffolk Life, which is based in Ipswich, Suffolk, dispute his allegations.
Mr Neal told Mr Justice Leggatt that Shearer's claims were "just driven by pure greed and ego".
Suffolk Life lawyers said Shearer faced "very serious obstacles".
Shearer and wife Lainya were in court for the opening day of the trial.
Barrister Gerard McMeel, who is leading Shearer's legal team, told Mr Justice Leggatt that claims related to pension investments.
Mr McMeel told the judge, in a written case outline, that Mr Shearer had "limited knowledge or experience" of making investments.
He said Mr Shearer and his wife relied on professional advisers and "those with responsibility to look after their interests".
Mr McMeel said claims centred on decisions made relating to a personal pension which had been worth more than £4 million.
He said Mr Shearer was accusing Mr Neal of "fraud" and a breach of fiduciary duty and accusing Suffolk Life of a breach of fiduciary duty and a breach of regulatory duties.
Mr McMeel said Mr Shearer had been given "negligent investment advice" and wanted £9 million damages.
The judge told Mr Neal, who is representing himself at the trial, that he was being accused of being "careless" and "dishonest".
Mr Neal suggested that the judge would have to decide whether the Shearers were "naive" or "sophisticated" investors.
He said the Shearers had made "serious money" out of one investment fund.
They had "pushed me" to put more money into one fund, he said.
He said he had not been "gung-ho".
"My feelings are very strong," he told Mr Justice Leggatt.
"I believe that I acted in good faith at all times."
He added: "This claim is just driven by pure greed and ego."
The trial is expected to continue into next week.