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

I'm not sure if he is/was trialling but I don't imagine we would sign him unless we lost a player. 

We only have 2 squad spots left. 1 is going to be a Chinese player and the other Ernie Merrick confirmed will be an attacking marquee player. 

Unless we lose one of: Alessi, Cowburn, Hoffman, Katroumbis (sp), Vujica, Boogaard, Jackson - I can't see it happening. And I can't see us losing any of those guys. 

Yeah, I agree. With a minimal number of squad positions available, you wouldn't expect a team to sign an unproven squad player.
Some of our signings have been decent, however I am really hopeful that the final two will be able to add a lot to the squad. A well known Chinese player or one of decent pedigree needs to happen. Ma Lei Lei sometimes showed quality, but we need someone who is more consistent. I'm really hoping for a decent marquee too. 
It's been a while since we have had something exciting to cheer about, but it looks like this team is heading in the right direction.

He is still trialling with the Jerks. Was on the teamsheet for our first trial last night:



From what I hear, he is basically training/trialling with us and we will look to sign him if/when our first injury happens.

Interesting. At least they are getting a good look at him, and he is also keeping himself fit (and possibly in the shop window). We tend to get a lot of injuries, so is at least forward thinking ;)

The Herald reporting we're trying to offload Daniel Alessi:

http://www.theherald.com.au/story/4795896/friendly-livestream-cancelled/?cs=306

Maybe paves the way for Adelson?

This is an interesting development. It may be why they've penciled him in. If Alessi has been unsettled for a while, it could explain Adelson's presence.

Adelson signs on a 2 year deal:

http://www.theherald.com.au/story/4814912/jets-hand-adelson-an-a-league-lifeline/?cs=306

https://www.fourfourtwo.com.au/news/jets-sign-ex-mariners-defender-469390