The 32-year-old midfielder damaged knee ligaments in a 2-1 win at Valencia on October 22 but returned to training last week and has been declared fit to take part in the first Clasico of the season.
Head coach Luis Enrique told reporters at his news conference: "He's not just the captain, he's the centrepiece of what our style is all about.
"He offers a lot on and off the field. It's good news, not just because of him as a footballer but what he brings to the team."
Luis Enrique also confirmed defenders Gerard Pique and Jordi Alba are fit to play after overcoming injury concerns.
"They are in the normal situation of players that have taken knocks, whatever type that might be," he said.
"They are available, they trained today, they can compete."