O'Neill was signed from Mansfield in the summer of 2012 but has appeared only twice for us, one of them as a last minute substitute at the end of his first season. Other than that he's played his football out on loan.
He spent time with both York and Southend in 2013/14 and last season played 21 Football League games with first Scunthorpe and then Leyton Orient.
His first loan at Southend, which started in January 2014, lasted less than half a game when he suffered an injury in his debut against Chesterfield, and after completing this recent loan was an unused substitute against Swindon.
But, speaking to the Southend Echo, he's expressed an interest in making a permanent move to Roots Hall, something that manager Phil Brown has also hinted at.
O'Neill said: "We have spoken about making the move permanent and I'm really interested in doing that to be honest. Hopefully we can get something sorted because I'm 24 now and I want to be playing and competing at a good level.
"League One is definitely a good level. I played in it last season and I know I can add something to this team."
The injury he sustained on his Southend debut in 2014 came in making a cross field pass and of that he said: "It was a good pass but hopefully I can do things like that again for longer. It was a shame to come off injured and I was actually out for quite a while with that, but it's fine now though and I'm raring to go.
"Being here before has helped me settle in because although I might only have played one game I was actually here for a while. I went away with the lads and they're a great bunch. The manager is good and it's closer to home for me too. My family live in Northampton so it's not too far and I want to be among things again."
He added: "The move has been on the cards for a while. It seemed to be taking a while and I thought it might have been done quicker, but I'm pleased to be here now and I just want to be playing games."