The Potters boss shared responsibility for the club's plight, but hinted that he is keen to remain in charge in the Championship next term.
"Players have let themselves down, as everybody knows. You start the season okay, then it drifts," he told reporters at a press conference.
"Collectively we let ourselves down. We didn't score enough goals or see games through.
"I always look myself in the mirror. I have done everything I can to put this club in a healthy position. I never did it, but there's a great chance to rebuild it."
Lambert will learn whether he will remain in charge of Stoke after this weekend's visit to Swansea City.