Cristiano Ronaldo injury: Real Madrid forward to undergo stem cell treatment before Champions League second leg

The Portuguese forward hopes to return for next Wednesday's semi-final against Manchester City

Ronaldo was not included in the matchday squad for Tuesday's goalless draw (Getty)

Cristiano Ronaldo will undergo stem cell treatment as he attempts to recover from a thigh injury in time to face Manchester City.

The Real Madrid forward was not included in the matchday squad for Tuesday’s Champions League semi-final first leg at the Etihad Stadium, which ended in a 0-0 draw.

Zinedine Zidane's side looked blunt in attack without their leading scorer and the tie is delicately poised ahead of the return leg, due to be played at the Santiago Bernabeu next Wednesday.

Ronaldo, who is likely to be sidelined for Saturday’s trip to Real Sociedad, underwent further medical tests after returning from Manchester but his club are yet to release a statement on his fitness.

"The issues which Cristiano had have not cleared up,” said Emilio Butragueno, Madrid’s director of football, said following Tuesday’s goalless draw. “It's better that he does not play."

It is believed that head coach Zidane will not know whether Ronaldo will be available for selection until the day of the second leg.

Ronaldo’s mother, Dolores Aveiro, claimed that her son will have recovered in time to play against City while speaking at the launch of a biography about herself.

"He is fine, he is not at 100 per cent, but he is at 80 per cent," she said. "I think that he will be back next week."

"Ronaldo is a person who always wants more," she said, when asked whether her son should accept that, sometimes, he needs to be rested.

"He is like his mother. He has a strong personality, he is very proud and he always demands more. This is his worst defect."