Zola led the Hornets to the play-off final last season but this term has been a different story and they have lost their last five matches at Vicarage Road which included the weekend defeat to Sheffield Wednesday.
Asked if his position was in doubt, Zola told the Daily Mirror: "I love what I do and I'm responsible for what I do - and I know that if I'm not doing a good job, I do something else.
"That's what I have to consider. I love being here, but I want to be helpful - and if I'm not, someone else will be.
"The fans have always been supportive and good to me, but this is a game where you need to get results and not just play good football.
"There has to be an end product, and in the last nine games (four draws, five defeats) we have not always produced that."