Florian Thauvin, Gini Wijnaldum and Daryl Janmaat are all included despite speculation about their futures.
Goalkeeper Tim Krul isn't on the flight as he continues his return from injury - but surprisingly, Rob Elliot has jetted out.
Krul and Elliot both injured their cruciate knee ligaments last season, with the Dutchman suffering his blow in October compared to Elliot in March.
Since then, Rafa Benitez has signed Belgian stopper Matz Sels, throwing Krul's future into doubt, and the speculation will continue after he was left on Tyneside along with Massadio Haidara and Emmanuel Riviere.
Benitez's 26-man party for the County Kildare-based camp, which will conclude with a friendly against Bohemian on Saturday sees Sels joined by fellow new boys Jesus Gamez, Matt Ritchie and Dwight Gayle.
Youngsters Adam Armstrong, Rolando Aarons, Kevin Mbabu, Jamie Sterry and Paul Woolston are also involved.
Newcastle United squad: Rolando Aarons, Vurnon Anita, Adam Armstrong, Jack Colback, Karl Darlow, Siem de Jong, Paul Dummett, Rob Elliot, Jesus Gamez, Dwight Gayle, Yoan Gouffran, Daryl Janmaat, Jamaal Lascelles, Kevin Mbabu, Chancel Mbemba, Aleksandar Mitrovic, Ayoze Perez, Matt Ritchie, Henri Saivet, Matz Sels, Jonjo Shelvey, Jamie Sterry, Florian Thauvin, Cheick Tiote, Georginio Wijnaldum, Paul Woolston