Former Premier League striker Michael Chopra said players would bet sums of £30,000 on the team bus and his gambling addiction became so bad he would set his alarm for 3am so he could place bets on games in South America.
Chopra, who was giving evidence at Newcastle Crown Court as a witness in a £750,000 cocaine trial, went into detail about the level of debt he got into and how he and his family were threatened by loan sharks.
He told the court: "I started gambling when I was about 17, when I first played for Newcastle I was travelling with the first team. Players would gamble on the bus and I got involved. We would take thousands of pounds onto the bus, anything up to £30,000.
"It might change hands playing cards on the bus, we would go to the bank before and take out the money. It was part of team bonding. We were playing for real cash, if you were playing for £30,000 you would have it with you at the time."
He also revealed that after playing for Newcastle and Cardiff, the reason he then signed for Sunderland was to use the signing on fee to pay off his debts.
"I was at Cardiff for one year and then I went to Sunderland. I got a signing on fee and paid my debts off. The main reason I went to Sunderland was to pay my debts off," he said.