As someone who's worked in the football press, I thought I might offer an insight into how this industry actually works.
In my first job we had a sit-down meeting once where everyone tried to come up with plausible links between players and clubs. It was a case of 'ok, Hulk's looking for a new club and United don't have a partner for Rooney, so we'll link them together.' There was no evidence for any of the links we came up with. I stress that I wasn't working for one of the big boys, but I think it happens all over the place, particularly the tabloids.
Then you've got the cowboy journos. There was one guy, called Ben Fairthorne (I think his stories are banned on the Caf), who used to cut-and-paste bits of existing interviews and pass them off as his own. So his 'exclusive' with, say, Messi would be a patchwork quilt of five or six different interviews Messi had done over the years. I don't know how many such cowboys are currently operating within the football world, but I guess there's quite a few.
Another place I worked simply copied articles from other papers, although I guess this is a bit more transparent as they are obliged to name and link to the source in the story. Loads of titles operate in this way - it's far easier to rip other people's stories than it is to actually do the work on your own. So you get the sort of wildfire spread which has erupted over Mourinho today. One paper claims the exclusive (which could be complete bollocks) then everyone has it.
Occasionally someone actually has an inside source (such as the guy who was leaking lineups at United under Moyes) but these avenues generally get shut down very quickly. All journos have to go on is the mixed zone, where you might get five minutes with a player; the corporate press day, where you're given a player and a list of questions to avoid; and the press conference, where most interesting questions are banned and the heavyweight journos have a pact to share the same the information they receive. One of the journos actually writes up everything that's said in the press conference and sends it to the other journos.
So basically, 90% of what you read is BS. The foreign journos are far more clued-in than the British ones tbh - people like Balague and Di Marzio actually have contacts. I wouldn't read anything into the UK-based reports.