Most of the comments on the articles tend to think it's Danny Murphy. I used to think it was Kevin Davies when I first started reading it. Can't remember what it was exactly but a few things written over a few weeks made me think him.
In one article recently about the FA Cup 3rd round draw he mentioned a few potential clues such as having played for a lower league team at Anfield and some team that he would have played against in that league at the time being drawn against a Premiership team this season. In the comments someone went through everything mentioned and worked out it could be Jason Roberts as he played at Anfield for a 3rd division side in 97/98 or some season that far back, and another team in that division that season was this season playing someone big etc.