Although he has a good relationship with his chairman Randy Lerner, he does not feel immune from the sack and always works with "that fear" of losing his job.
Returning to the theme this week, Lambert said: "I never stop worrying. I'm not immune from it.
"The relationship between me and Randy is what it is. You are never immune from anything, and I would never view it that way.
"You just keep going - there is no secret formula to it. You just keep going and don't lose focus on what you are trying to do. I will never waver from that."