Sir Alex Ferguson has revealed that there is "no limit" on how long he will remain in the Old Trafford hot-seat.
Ferguson is in his 22nd season in charge of United, and the 66-year-old admitted that he may well prolong his reign - providing his health permits him to.
"It's something I've said for quite a bit - If your health is good and you're enjoying your job it could be two, three years, who knows? Ferguson told Sky Sports News.
"It could be four years who knows? It could be tomorrow if I read some bad press from your mob [journalists] - trying to get rid of me," Ferguson joked.
"I've not put a time limit on it - that's for sure."
Ferguson has a near full-strength squad to choose from when his side take on Portsmouth in the FA Cup quarter-final at Old Trafford on Saturday, live on Sky Sports 1.
With domestic league and UEFA Champions League duties in the back of his mind the United boss may choose to shuffle his pack.
The Scot revealed that he is happy with the progress of long-term injury victims Gary Neville and Mikael Silvestre and is confident the England international will shortly be returning to first-team action.
"Everyone is fit for tomorrow - obviously Gary (Neville) and Mikael Silvestre are on a good programme now and I'm pretty positive about that - particularly Gary who is doing much better," Ferguson said.
"It is a matter of sticking to that framework of what we're doing with him to make sure he doesn't have anymore niggly re-occurrences of the small injuries that have been holding him back."
Ferguson praised the strength-in-depth he has at his disposal, and views Saturday's clash as a perfect opportunity to progress into the final four.
"Everyone else is fit and obviously I have a difficult choice to make and that seems to be the norm at the moment with everyone being available," Ferguson said.
"But that is something I'm happy to do because without that squad we wouldn't be where we are at this moment in time.
"Obviously it's an FA Cup tie, it's a quarter-final, it's at home - it's all we can ask for as I keep saying.
"It should be a good atmosphere tomorrow and we have a test - it's a good test for us and hopefully we can come through it."