The former Ipswich Town forward will give evidence in relation to £50,000 in cash discovered in a Jaguar car, which the prosecution claims is drug money.
Defendant John Somerville's legal representatives argue that their client was using the £50,000 to pay off gambling debts that Chopra had run up.
"That £50,000 that was found in the car was nothing to do with drugs," the Daily Mail quotes lawyer Richard Bloomfield as saying. "That £50,000 was Chopra's. It was to pay off a gambling debt, to pay them off.
"That was what John Somerville was doing on November 11, 2010, he was not buying drugs, he was paying Michael Chopra's gambling debts off."
Four men accused of conspiracy to supply Class A drugs have denied the charges at Newcastle Crown Court, where the trial continues.