The midfielder headed home the only goal of the game as the Magpies beat Crystal Palace on Saturday.
“It's only a matter of time before the very top clubs come looking at him, but we want to be a top club, too.
“We want him to stay here, we don't want to see any of our top players up for sale again.
"He's a fantastic signing from the manager and the scouting department and hopefully we'll just see him develop as a player and he fulfils all that potential at Newcastle.
"It's brilliant news he's signed permanently, great for the club that such a talented young player has committed himself."