The 21-year-old could be set to make his debut against Bohemians this weekend.
The 21-year-old, who made just two appearances for Arsenal after emerging from the youth team, signed for the club on Monday, and has now joined up with the squad in preparation for Saturday's game against Irish outfit Bohemians.
The new signing was shown warming up alongside Jamie Sterry wearing the number 14, and took part in training both in the gym and on the pitch, with other new members of the club such as Dwight Gayle, Matt Ritchie and Matz Sels also present, in the Chronicle's gallery.
Hayden signed for the Magpies after a successful campaign on loan at Hull City last season, helping the Tigers achieve promotion during his 24 appearances at the KC Stadium.
There was some surprise when Arsenal agreed to sell the youngster to the Magpies, but it is Rafa Benitez and Newcastle who may now benefit from Hayden's qualities as the Tyneside outfit look to bounce back from relegation.
Burnley's George Boyd and Isaac Hayden in action