According to James Gardiner's twitter, Jake Adelson was trialing with Newcastle (as of 26 June). He's a player that has oodles of potential, but has had 2 serious knee injuries and has therefore not had a chance to reach that potential so far. He's a RB, which is a position Newcastle tend to struggle with, so could add depth, if he gets a gig. However, apparently there was no promise of an open position there. If he manages to get a contract, he would most likely be a squaddie, as they have Hoffman, as well as Cowburn, Vujica and Georgievski across the fullback positions. 
Source: https://twitter.com/JamesGardiner42/status/879502522603282433