The Spain international's recovery schedule is running smoothly and he could be fit again by the middle of March.
The goalkeeper broke his thumb in the Copa del Rey clash with Valencia in January and underwent surgery to correct the problem.
The operation saw the Blancos captain undergo total reconstruction of his thumb and two screws were inserted, both 17 milimeters long and two millimeters wide.
"I have a month to go. Things are really looking up," he told reporters during the opening ceremony for the new club shop at the Bernabéu. "The doctor expects me to be back in another four weeks. I'm doing active exercise and I can move my finger now."
However, Casillas will have a fight on his hands to reclaim his starting slot, having been dropped by Jose Mourinho prior to injury and with Diego Lopez arriving from Sevilla.