Lewis has come under fire following recent errors but redeemed himself to some extent with a penalty save in the 1-1 draw at Huddersfield last week.
"People can say what they like from the stands but if the manager's backing me that's what gives me confidence," Lewis said.
"When the manager feels I'm not doing the job properly and he drops me that's when I'll start to worry.
"I don't generally read the papers or listen to the press, people have their own opinions. A goalkeeper that doesn't make mistakes just doesn't exist, but when you make them you come in for criticism just like everybody else.
"It was nice to make the penalty save but I didn't take any greater pleasure out of it because it was proving somebody wrong. Unfortunately it didn't win us the game but from a personal point of view it's given me a boost."
Source: PA
Source: PA