But Fuller told BBC Radio Kent: "That was a massive blow but we've got to go into these games and give it 110%.
"We'll try not to go mad but if there's a 50/50 tackle - then telling me that is like telling a dog not to bark."
Fuller added: "Losing King was a real blow because he's a top centre-half - to lose a player like that in a game that is mainly for fitness is obviously disappointing.
"It's always in a player's head in pre-season as no-one wants to pick up any type of injury, even a little niggle, as no-one wants to be missing games.
"If we can get through pre-season with no injuries we'll be over the moon."
Source: BBC Sport
Source: BBC Sport