Few would have predicted a subsequent 16-year absence from the Premier League, but perhaps if they had not made a string of blunders in the transfer window they might never have been relegated at all.
The latter sale would have hit even harder given how late in the window it came, and at just £7m, it was hardly outstanding money, even for the time.
At Elland Road, the Irishman had scored 18 times in just 56 games, but his move to London saw him become something of a hero for Spurs. He would score 122 times in 306 appearances, also chipping in with 31 assists.
It marked a huge blunder from the CEO at the time Peter Ridsdale, who had clearly undervalued just how important Keane could be for his club.
His longevity was a huge part of his game too, as he featured for club and country for a remarkable amount of time.
Although he did not gather a huge trophy cabinet after his move to the Lilywhites, he still played plenty of top-flight football on his way to just one League Cup victory.
Had he stayed, he may well have fired Leeds to safety. But that clearly was not a risk he wanted to take, as he jumped ship not soon after Ferdinand.
To lose both of these figures in one summer is hard enough, but that late in the window was a killer.
They survived for two more seasons, but players of his calibre are often impossible to replace. The task became insurmountable, marking a terrible transfer decision by the club.