Long-running contract talks with Simpson broke down last year, and he lost his place in the team to Mathieu Debuchy, who joined from Lille in January.
Simpson was on £15k a week, while Mike Williamson is on a staggering £40k.
While the 26-year-old had hoped to commit his long-term future to Newcastle, he insists there were no arguments behind the scenes.
Danny Simpson: “There weren’t any arguments.
“It’s football – these things happen.
“The fans need to know I wasn’t being greedy.
“It was just one of those things – I think the club wanted to go in a different direction. I knew that even when they offered the contract. I knew someone was going to come in.
“Mathieu came in, and I didn’t want to be sat on the bench. I’m 26, and I want to keep playing football.
“I’m not one of those players who’s happy to sit on the bench and take the money.
“I want to play football. I buzz off playing every Saturday.
“Sometimes both parties need to move on. I just want to say thank you to everyone, and move on.”
Source: Newcastle United Mad