Venables wrote in The Sun: "Lambert must be the leader and step up to the plate.
"He must be so down. But he can't afford to let that filter through to his players who must also be on the floor.
"They will be looking at him and taking their lead from him. So he has got to come in every morning bouncing and jolly.
"Not only must he be a good manager but he has an acting role on his hands, too.
"He's got to be all smiles and confidence, even if those around him are thinking, 'What's all that about?' and 'Why is he so happy?'
"But that is what he must do. He also must remind himself to keep doing the things that made him a success in the first place."