Sky sources understand that Chris Powell has been sacked as Charlton manager.
Powell has come under increasing pressure after a dismal run of results left Charlton rock-bottom in the Championship and Sunday's 2-0 FA quarter-final defeat by League One Sheffield United has prompted the board to act.
Belgian owner Roland Duchatelet had been in talks with Powell over a new contract, but he has now lost patience with the former England full-back and is understood to have already lined-up his replacement.
Jose Riga will be the new man in charge with Karel Fraeye working as his assistant, and he has already arrived in London.
Riga is currently technical director of AC Milan's academy, but previously had a spell in charge of Belgian club Standard Liege who are also owned by Duchatelet and from whom a number of players have been loaned from since he took-over at The Valley earlier this year.
Charlton are four points adrift of safety, but have four games in hand over some of their relegation rivals.
It remains to be seen whether the new man will be named before Saturday's home clash against Huddersfield and Charlton then travel to fellow strugglers Millwall the following weekend.