ITV's three external teams, headed up by Ben Allen, Simon Orpin and Jeremy Lawrence, who report into Digby and his deputy, London sales leader Simon Lent, face a major overhaul.
TV insiders say the three teams will be cut to two with possible job losses, however Digby said such speculation was "simplistic."
He added that the aim of the restructure was to reflect cross-media moves, such as the purchase of Friends Reunited, allowing ITV to exploit new areas like online, sponsorship and product placement.
He said the current ITV Sales set-up wasn't equipped to cope with the massive changes going on in the market.
"We're going to go through a whole process of how we structure the sales division," he said." The world is changing so quickly and we don't have a structure to facilitate it. "
"There will be a lot of retraining. We've come from being a monopoly. We've been very negotiation focused.
"Our teams are structured to deal with a market dominated by spot ads, where six years ago you could put anything on the box and get nine million viewers."
Meanwhile, speculation continues over the future of ITV's director of customer relationship marketing, Justin Sampson.
ITV was due to make an announcement on Sampson yesterday (Monday), but then didn't issue one.
ITV insiders say he will leave the company shortly, and it now seems unlikley that he will be appointed as Thinkbox's first full-time chief executive.