Defoe sat out the 2-1 fourth-round loss at Elland Road due to a pelvic muscle injury and with Emmanuel Adebayor, the only other recognised striker in the Spurs ranks, currently away with Togo at the African Nations Cup, Villas-Boas has limited options in attack.
But Villas-Boas said Defoe had undergone scans and had a plasma injection to allow him to be fit for the Barclays Premier League trip to Norwich on Wednesday night.
When asked about the extent of Defoe's injury, Villas-Boas said: "He felt some tightness. It was a grade one injury to his obturator muscle which was treated immediately.
"We acknowledged that resting him for Leeds was almost compulsory so we left him out of the game and he has made an excellent recovery so he is back.
"In muscle injuries there is always a risk of it showing up again, but the medical department feel positive about it and the player is positive and he knows his body well."
Villas-Boas revealed Spurs are keen to use such innovations to the benefit of their players and ruled out the need for 30-year-old Defoe to need an operation and miss a large chunk of the season.
"We believe a lot in growth factor treatment and plasma platelet treatments," he said. "It is a technique that we have been using since the beginning of the season.
"It is not common but does happen from club to club. The player adhered to the treatment very, very well so we can move forward.
"You take out the blood from any part of the body and spin it around. The plasma comes to the top of the blood and you are able to inject it back into the body and that is the part of the blood that heals injuries. It accelerates the recovery process. The day he felt the injury was Friday and he had the injection thing. Now he is available for selection. That is the remarkable thing."