BBC Sport (or any other media outlet) 'understands' ...... although this covers all sports not just footie.
It seems to be the by-line for anything these days, normally meaning they've just made it up ....
... or they've hacked somebody's phone and can't say so 'cos that might get them in the poo!
Example this morning:
Johan Cruyff is among the names being targeted by Liverpool after Damien Comolli's departure as director of football, BBC Sport understands.
Perhaps should read:
Johan Cruyff is among the names being targeted by Liverpool we came up with, while standing around the coffee machine, after Damien Comolli's departure as director of football, BBC Sport understands speculates.