"We will cross that bridge when we come to it," he said, "but we haven't even discussed it yet.
"It's not like a normal business where you can plan. It is about who is in vogue. You can have ideas of another manager who you think is great and then a season later he's out of favour. Stuart Pearce, for example, was touted as the next England manager and then suddenly he loses his job [at Manchester City].
"We believe we're building a first-class squad with Sir Alex and the age of the squad is really good. As he said the other day, he will, ultimately, retire, and at that point the squad that his successor inherits will hopefully be an extremely good squad."
Two former United players, Mark Hughes and Roy Keane, are both seen as front runners to succeed Ferguson having impressed at Blackburn Rovers and Sunderland respectively, but Gill admits that United's recent return to prominence underlines Ferguson's continuing hunger and ambition.
"We recognised that 2005-06 was a difficult season and that Chelsea were way ahead, but it always looks a bit more out of control and doom and gloom from the outside. You get those phases and Sir Alex is experienced to know that things turn around pretty quickly," Gill said.
"His plans for the squad, which he was working on with Carlos Queiroz, were moving in the right direction. I think there has been a transformation and it has been very positive and last season was great."