The midfielder was injured in loan action for Norwich City against Sheffield Wednesday at the weekend and now faces up to three months out after scans on Tuesday revealed a rupture in his Achilles.
Head Coach Martin Jol reported: "I hoped on Monday it would only be four weeks but he will be out for two or three months, so thatÃ¢â‚¬â„¢s a blow to the lad.
"He was doing well at Norwich, playing almost all the matches and that was good for his development.
ItÃ¢â‚¬â„¢s a setback but we go on and when he comes back he will start all over again
"I'm bitterly disappointed," said Deano. "The big thing about going on loan was to play games and that's exactly what I was doing.
"I was enjoying playing regular football at Norwich and this has come as a big blow. I'd just had three weeks out because of a knee problem, came back, played two games and now this has happened.
"All I can do is try to get fit as quickly as I can and hopefully I'll be able to go back, play more games and then return to Spurs at the end of the season."
Dean Marney was naturally feeling at a low ebb back at Spurs Lodge this week as he faces up to a spell on the sidelines.