Thomas Sandgaard has said that he would not confirm Mason Burstow's transfer to Chelsea until the loan back deal was agreed. With Jayden Stockley likely to be out for much of the rest of the season, his availability is a key asset: https://londonnewsonline.co.uk/charlton-supremo-rejected-chelseas-overtures-until-mason-burstow-loan-back-was-agreed/
Sandgaard also revealed that the sell on clause was 'exceptionally high'. This will be important if Burstow does make the grade. Whether or not he will remains to be seen but for him it is a risk worth taking.
Sandgaard confirmed that Brentford was the other club to make an offer, but there is no substance in rumours that they were prepared to pay £3m.