Alexis Sanchez's move to Manchester United was a "once in a generation opportunity" to buy a top player for little money, according to former Liverpool managing director Christian Purslow.
The Chile international was one of the most high-profile acquisitions during the January transfer window, the 29-year-old moving to United from Arsenal in a swap deal that saw Henrikh Mkhitaryan go in the opposite direction.
Sanchez, courted by Manchester City last summer, appeared set to reunite with former Barcelona manager Pep Guardiola at the Etihad but Jose Mourinho made the forward his principle January transfer target, with Chelsea also having held an interest.
When asked whether anyone in the game saw anything other than a Sanchez move to City before the window opened, Purslow told Sky Sports News: "I don't think they did. I think everyone thought that was a done deal.
"We will never quite know the sequence of events that led to that potential transaction winding away into a United purchase.
"It has the look from the outside, I don't know this to be true, that Arsenal out of nowhere had their dreams come true.
"Rather than being in a unilateral discussion with City taking their best player nearly on a free they had a little auction going when Mourinho and Antonio Conte both spoke up in early January that actually getting Sanchez was a once in a generation opportunity to buy a top player for not much money down."
Manchester City are understood to have withdrawn their interest in Sanchez after they believed the potential deal, provisionally agreed at £60m with Arsenal in the summer, had become too expensive after competing offers were tabled.
Purslow described the shift in direction over negotiations for Sanchez as a "breach in trust" and conceded the move was a "brilliant outcome" for the Old Trafford hierarchy.
"I think Arsenal suddenly had a little auction going. I suspect when Sanchez's agent said to Manchester City's executive team you might have to improve my deal up a bit because United are here - that [would have] felt like a breach in trust," he added.
"They thought they had a handshake deal at best. I bet they were very angry about that and I suspect they thought actually let's walk away from this deal leaving Manchester United to sweep him up.
"Brilliant outcome for United, pretty good outcome for Arsenal on balance but I suspect not a very happy camp at City around the way that deal was conducted."