Gallas believes that Chelsea should back Gallagher and reward him for his contributions with a new contract.
Speaking to Lord Ping, Gallas said: "Should Chelsea sell Conor Gallagher? When you spend £100m plus on players like Enzo Fernandez and Moises Caicedo, they will have big expectations and you expect them to lead on the field. It hasn't happened, they're still young. Conor Gallagher is a Chelsea boy, he did not cost the club any money and the fans love him because of his commitment on the pitch.
"Gallagher runs a lot, you need players like him, if you compare him to Enzo and Caicedo, he is completely different. Gallagher is doing more for Chelsea than the other two, if he has to leave the club, the fans will be upset but they will understand why he has to leave, because of Financial Fair Play. It's hard to understand how Chelsea have put themselves in that position, the board has made a mistake in spending so much money that they now need to rely on selling homegrown players."