Victory will guarantee Spurs a place in Europe's top competition next season, while if City claim fourth place the immense wealth of owner Sheikh Mansour bin Zayed Al Nahyan could see some truly world class talent make its way to east Manchester this summer. And Redknapp has already experienced the power and wealth of City when the two clubs were involved in a bidding war for forward Craig Bellamy in January last year.
"They blow you out of the water," said Redknapp. "We tried to sign Bellamy and, at the time, we were after Wilson Palacios as well. "They said: 'If you don't drop out of Bellamy, we're going to sign Palacios. We're interested in Palacios. But if you pull out of Bellamy, we'll pull out of Palacios and then we both get a player.'"
Redknapp himself was no shrinking violet during that winter 2009 transfer window - shelling a total of £42million on Palacios, Robbie Keane, Jermain Defoe and Pascal Chimbonda - but competing with City proved to be a bridge too far.
"They wanted Bellamy badly. It was when Mark Hughes was there, and obviously he was close to Bellamy, The Welsh connection. They were desperate for Bellamy. We were having a bidding war on Bellamy over the fee.
"So we had no choice really. They just said 'We'll blow you out of the water'. They've got the backing, they've got the clout to do that, they can do it if they want somebody."
Whatever the outcome on Wednesday, and a draw would see both teams take the fight to Sunday's last fixture of the season, Redknapp insists they have exceeded all expectations from the moment he took control of relegation-haunted Spurs in October 2008.
"We have exceeded expectations definitely. When I took over here I discussed targets with the chairman, it wasn't European football, it was to make sure we did not get relegated.
"We were bottom of the league and chairman Daniel Levy had not slept for a couple of weeks so I helped him sleep by getting us out of trouble.
"I didn't come here saying 'I'll get you into the Champions League, Daniel'. But he's sleeping well now, especially with the chance of getting into the Champions League."
Source: PA
Source: PA