The Portugal winger has been out of action since Oct. 10 because of an ankle injury, but is set to play some part at the Santiago Bernabeu stadium as the Spanish leaders look to clinch a place in the knockout stages.

"Cristiano is in the squad," coach Manuel Pellegrini said Tuesday. "He's looked a lot looser in the last few trainings, so we'll see how much he plays tomorrow."

Madrid and AC Milan lead Group C with seven points, while Marseille has six and Zurich three. A Madrid victory would knock Zurich out, while a Milan win in the other group match would allow the two leaders to advance with a game to spare.

Madrid will welcome Ronaldo's return to a disjointed team that has come under heavy criticism for its play.

But Pellegrini's side has still managed to assume top spot in the Spanish league, with Saturday's 1-0 win over Racing Santander giving it a one-point advantage over defending champion Barcelona going into their "clasico" derby match on Sunday.

Ronaldo, who joined Madrid for a record ⁈lion ($135 million) from Manchester United in the summer, scored two goals as Madrid beat the Swiss champions 5-2 to open group play.

Zurich, meanwhile, has failed to latch onto the momentum gained from a victory over Milan at the San Siro, having dropped both matches against Marseille since _ including a sound 6-1 defeat.

Zurich midfielder Xavier Margairaz said the club's debut campaign in the Champions League had stretched its playing resources.

"Its the most important competition for a club, and it burns up so much physical and nervous energy," Margairaz said. "At certain times we should play more with the head, but all this is going to serve us well as experience."

Zurich can pay about half of its entire annual budget with the ⁈llion ($11.8 million) in bonus and prize money it will earn. But it has won only one domestic match since playing Real and stands eighth in the 10-team division to trail leader Young Boys by 15 points.

Zurich is without midfielder Onyekachi Okonkwo due to suspension.