Charlton is demanding a major improvement after his men lost 28-20 at Keighley last week.
He said: “We were very poor in the first half and that’s something we need to put right.
“To me, it was probably a bit of complacency among the players and maybe a bit of disrespect. We got what we deserved.”
He added: “The players all understand that that performance wasn’t up to the standards expected.
“We’ll need to be a lot better this week. Leigh are a good team, they play some good rugby if you let them, and they can put a lot of points on you. We’ve got to start right.”
Fifth-placed Leigh are four points adrift of the top four after last week’s home defeat against Featherstone Rovers.
Centurions coach Paul Rowley said: “Workington are a very good team and we’ve got to be ready to face that challenge.”