Diaby and Isak emerged as top targets for Newcastle this summer as Eddie Howe looks to add more quality to his attacking resources ahead of the new season.
But Newcastle have been forced to abandon their pursuits of the two forwards due to excessive demands in terms of transfer fees and wages.
Newcastle are not prepared to pay over the odds and are now back to the drawing board as they sift through another set of targets.
The club are now looking to sign someone younger or less well-established in order to get more value for their money.
Newcastle have already spent more than half of their transfer budget and have been considering spending the rest of their kitty on one forward.
However, the club have been forced to leave the pursuits of Diaby and Isak due to demands made by the clubs and their agents.
Bayer Leverkusen wanted £60m upfront for Diaby and Real Sociedad insisted that they do not want to sell for anything less than Isak’s £76m release clause.
Newcastle also baulked at the wage demands made by the Sociedad striker who wants a contract worth £200,000 per week.
The Magpies have been left frustrated that the clubs were not prepared to negotiate from a realistic position in terms of the market value of the players.
