"Ashley is ready to play," manager Carlo Ancelotti told a news conference on Monday. "Yesterday he trained and we will monitor his progress again tonight but he is good to play."
Ancelotti also has Didier Drogba back in his Champions League attack after the striker missed the opening three games of the campaign through suspension.
European soccer's governing body UEFA banned Drogba for harassing referee Tom Henning Ovrebo after last season's semi-final defeat by Barcelona.
Sanchez Flores said wins on Tuesday and in Saturday's La Liga clash against city rivals Real could revive the club's season.
"It would give us a lifeline in both competitions and would also be positive for the players from a psychological perspective," Sanchez Flores said.
"But Chelsea are difficult opponents in every department and to beat them we'll have to be at 100 percent."
"We are ambitious and the Europa League would still be good," said Sanchez Flores.
