Fredi Kanoute lashed home the only goal of the game in the second half and we missed a host of chances before and after it.
"It was a very disappointing performance," admitted Keegan.
"We started off okay. But the longer the game went on, the more we were passing it around with no real purpose.
"We didn't look to have a goal in us, and there will be a few players who will look at their personal performance and not be very happy with it.
"If we have five or six players below par we will get beaten, and that is what happened. Spurs created all the best chances and deserved their win."
City boss Kevin Keegan had few complaints with our 1-0 victory over his side on Saturday.