Following the game, Zidane says that the problem is not a major one - but it does leave question marks over his condition with the trip to Kiev to face Liverpool just two weeks away.
And Zidane insists he can not afford to worry about further injuries in the coming league matches, preferring to pick his best available XI.
Indeed, speaking after the game Real manager Zinedine Zidane said: "We're not anxious about the final", before adding that "I can't say how long he'll be out for". "Even if we do not know when he will resume with the team, the fact that he is already there 48 hours after shows his commitment, his desire to always want to play".
Youngsters Jesus Vallejo, Marcos Llorente, Dani Ceballos and Borja Mayoral could all come into the starting XI for the game at the Estadio Sanchez Pizjuan, with Gareth Bale among those rested after the Wales international's third child was born early on Tuesday morning.
Ronaldo is expected to play against Liverpool on May 26 in the Champions League final.
Barca hold Madrid to remain unbeaten
A typically ill-tempered Clasico saw Barca reduced to ten men in first half stoppage time with the sending off of Sergi Roberto . Ronaldo scored against Barcelona on Sunday but came off at half-time after injuring his ankle in the 2-2 draw at Camp Nou.
He continued: "I believe that the Argentinian national team without Lionel Messi wouldn't be a contender". Thinking that way is not good, we must be positive. Though Barcelona only played with ten men, as their midfielder Sergi Roberto got a red card, the hosts were soon able to take the lead after Lionel Messi struck a goal in the 53rd minute of the match. "But with him nothing is impossible", the 55-year-old told ESPN Brazil. "This is football, we can not control it".
Ronaldo, scored his 25th goal of the season and 42nd in all competitions, when he cancelled out Luis Suarez's opener, but picked up a knock in the process.
'That's the situation. I think he will have a scan and then we will know more'. The game won't be Cristiano against Salah, it will be Real Madrid against Liverpool.