But it appeared the move would be blocked by FIFA regulations which prevent a player featuring for three clubs in a single season.
However, a FIFA spokesman has now confirmed Blackburn could appeal against the ruling, telling the Daily Record: "In general the rule does apply but if a club or player asks FIFA to look at any case it comes to the FIFA legal department.
"A typical example of this situation involved Carlos Tevez last season."
Faye has been training with Blackburn over the last few days but Rovers chairman John Williams remains in the dark about whether a deal can be pushed through.
"Amdy is on trial with us for the week with the approval of both Rangers and Charlton," explained Williams.
"But even if the trial proves successful there is still the issue with FIFA."