The Englishman is set to play his debut for the league leaders in Le Classique against their bitter rivals from the south coast.
“He may start because he’s fit enough,” Ancelotti told a news conference on Saturday. “I’m not surprised because I know him well. He’s always focused, he works hard every day, he’s a great professional.
“If I start him, he could play 60, 70 minutes. If he comes off the bench, he could play 30, 40 minutes.”