United wanted to sign Bale as cover for Patrice Evra.
Yet Saints opted not to do business, with the Wales international switching instead to Tottenham.
Since then, Bale has gone on to become a major Premier League force, having moved out of defence into a forward position, and has just scooped both major footballer of the year prizes at the expense of United striker Robin van Persie.
There have been hints Ferguson would make a move for Bale in the summer if Tottenham miss out on a place in next season's Champions League.
Such a transfer would cost United a sizeable sum, in all probability smashing their £30.75million transfer record when Dimitar Berbatov moved north from Tottenham in 2008.
And it all could have been avoided if Southampton had just returned that call.
"We were disappointed in Southampton because we were first there but they never came back to us," said Ferguson.
"He was a left-back when we tried to sign him from Southampton.
"He reminds me a bit of when we signed Lee Sharpe. He was a six foot, gangly slim boy but all of a sudden he was built like a light-heavyweight American boxer.
"Bale is the same given the way he has developed physically in the last two years. He has matured very well."
Confirmation of Van Persie being named April's Barclays player of the month for his six goals in five games underlines how unlucky the 29-year-old was to miss out on the prestigious Professional Footballers' Association and Football Writers' Association honours.
However, as the Dutchman's 10-match barren streak coincided with Bale's best form of the campaign, and voting for those individual prizes, Ferguson has few complaints.
"You can't dispute it," he said.
"Some of the goals Bale has scored this year have been fantastic.
"Robin is a little bit unlucky in that he hit a quiet spell and didn't score at a time Bale was bashing them in from all sorts of distances.
"There is not much between the two of them in terms of performances this season and that was reflected in the percentage of the votes."
Along with Robert Lewandowski and Radamel Falcao, Bale is one of the names most regularly mentioned as potential Ferguson transfer targets this summer.
However, executive vice-chairman Ed Woodward, who will replace David Gill as chief executive in the summer, said on Thursday he did not envisage a "major retooling" of Ferguson's squad given the manner in which they have claimed a record 20th championship.
Ferguson agrees a significant revamp is not needed but he is confident the Glazer family will meet his requirements.
"We have fantastic strength in depth," he said.
"That's the area where we don't want to confuse ourselves because you end up with too many players and having to try to keep them all happy. It's happened a few times this season.
"But any time we've asked for money off the owners they have delivered."
With a spending splurge from Manchester City likely and Jose Mourinho certain to make a big impact at Chelsea should he return to Stamford Bridge as suggested, United cannot afford to stand still though.
Wilfried Zaha has already been signed from Crystal Palace and Ferguson is expecting minor movement during the summer.
"We'll look at one or two bodies to come in," he said.
"You've got to take into consideration there are a lot of young players we expect to improve," said Ferguson.
"You have to consider their ages and protect that part.
"In the main we know where we are. We're comfortable."
There are some players who appear surplus to requirements though, including midfielder Anderson and wide-man Nani, both of whom have failed to match expectations since their arrivals in 2007.
Nani has made more of an impact but his contract is due to expire next year and so far, the respective parties are poles apart in their valuations. However, Ferguson insists no one is going anywhere.
"We have no plans to sell anyone," said Ferguson.
"That's a fact. There is no need for us to sell anyone. Nani played last week at Arsenal and he did well.
"When he is in form there are very few better than him. So I think we will bring him back in pre-season training and he will be all right."