The former Spurs keeper has been watching on from afar as all the optimism generated by a superb run in last season's Champions League has threatened to evaporate. Not only did Harry Redknapp's men fail to retain a place in Europe's elite club competition, now star man Luka Modric is demanding a move to Chelsea.
Keller expects Modric to get his way eventually, which would merely confirm his old club's status as sellers. He told Press Association Sport: "Spurs have had this problem for years. I don't see Manchester City selling their players to rivals. Manchester United don't do it. If you want to be one of the big boys you have to act like it."
To Keller that means retaining your top players and adding to them.
During his three seasons at White Hart Lane in the early 1990s, the 41-year-old got used to star men being sold on.
It was still happening three years ago when Dimitar Berbatov went to Manchester United and if Modric does end up at Stamford Bridge, it would appear nothing much has changed.
"Your best players should want to stay," he said.
"They should not want to leave because they know they are going to be challenging for trophies.
"Tottenham have to reach that stage. At some point they must make a decision.
"Are they going to honestly and truly compete with these teams or are they just going to hope it all comes together at the right time and challenge for a year or two?"
Source: PA
Source: PA