The Daily Telegraph claims that the club were unhappy with comments from Ba on Alan Pardew's long-ball approach, as well as remarks about a potential move to Arsenal in January.
Ba was quoted by The Newcastle Journal as saying: "I'm not happy when the team does not create anything.
"Fans come to see beautiful games with beautiful actions and not long balls from the goalkeeper to the striker."
Statistics show that Newcastle play the most long balls in the Premier League this season, but the tactics seem to be working for Ba, who has already scored 11 times this season.
That, along with a reported release clause in his contract of around £7.5million, has led to speculation that he could leave the club in January, and Ba didn't exactly dampen such talk.
He said: "Journalists just do their job.
"They know Arsenal need strikers, they know a release clause is inserted in my contract, so they make speculations.
"I don't really want to comment on that, because there hasn't been any contact, clearly, but it is true Arsenal are a very attractive club."