The club had a bid rejected for the Lyon midfielder in January and reports suggest Alan Pardew has renewed his interest - though Bernard feels a possible deal is unlikely due to an apparent difference in valuation.
|7/1||Newcastle are 7/1 with bet365 to be relegated next season|
"For the money that's been spoken about [for Grenier], it's never going to happen," Bernard told the Evening Chronicle. "I think if he goes, it'll be for £20m. It could even be a Champions League team.
"For me it will be a surprise if he goes to Newcastle. Sadly it could be a 90 per cent no for Grenier to Newcastle."
Newcastle finished 10th in the Premier League last season after a push for the top five unravelled at the turn of the year.
Bernard added: "The problem at Newcastle has been that when the club did well and finished fifth [in 2011-12] they didn't invest. Now it's a whole lot harder for them to attract players.
"We have not done well enough to attract some of the ambitious players. They want to see a club playing in the Champions League or even the Europa League.
"And Newcastle aren't close to that at the moment. I really think the Grenier deal is unlikely."