Neville, 34, has revealed that he has already started to plan for life after United by taking his coaching badges.
Related ArticlesUnited tarnished by link with disgraced AIGChampions League guideUnited face loss of AIG £14mUnited will retain 'disgraced' logoOne more year for Ferguson?But the former England defender who won 85 caps admits that he could yet turn his back on the game completely if he fails to find a challenge that matches his ambition.
Speaking to the Big Issue in the North, Neville said: "Part of me says I'd like to stay involved in the game, but another says I should do something else.
"It would nice to be able to take on a different challenge. I'd like to think I could do something else other than football, but the reality is that's what I've done since I was 16.
"I am doing my coaching badges, but whether anyone will want me as a coach or a manager I don't know.
"I don't know, even now so close to the end of my career, what will happen. But leaving Manchester United, in football terms, is like falling off the end of a cliff.
"I just hope there's something that I find exciting and can enjoy, and in which I retain the ambition to achieve something."
Neville has struggled to reclaim the right-back spot at United this term following his return to action from his lengthy injury lay-off.
The emergence of Brazilian teenager Rafael da Silva and the performances of Wes Brown have checked Neville's progress. But the veteran defender says he is ready to play whenever called upon by Sir Alex Ferguson.
Neville said: "I am just trying to keep myself fit and make myself available for the manager."