The Portuguese, who bagged a brace on Wednesday, was injured in the process of earning a penalty converted by Brazilian ace Kaka.

"Cristiano has some swelling and we’ll have to wait and see," coach Manuel Pellegrini said after the game at the Bernabeu.

"The state of the ankle shows that he took a hefty knock in the penalty incident. It’s still early to say whether he can play against Sevilla on Sunday."

Ronaldo has been instrumental for Real as the Royal Club won all their games so far this season, leading the Primera Liga and the Champions League Group C.

In the same manner, Real said that midfielder Fernando Gago is set for a three-week layoff after suffering a muscle strain during the match.

The Argentine will likely miss this month's qualifiers against Peru and Uruguay.