The Portuguese looked to have suffered a recurrence of his recent thigh trouble but Los Blancos have explained that his early withdrawal was simply a precautionary measure
The Portugal international was forced off just nine minutes into the game at the Jose Zorrilla with a suspected hamstring problem, thus casting doubt on his participation in Los Blancos' two remaining Primera Division fixtures, as well as the Champions League final against Atletico Madrid on May 24.
However, Madrid promptly claimed that Ronaldo's withdrawal was purely a precautionary measure and that the attacker was suffering nothing more serious than muscle fatigue.
The 29-year-old only returned to the Madrid starting lineup for the first leg of the team's semifinal with Bayern Munich at the Santiago Bernabeu last month, after missing four games, including the Copa del Rey triumph over Barcelona, through a combination of thigh and knee injuries.
The Ballon d'Or winner played a key role in Los Blancos' 5-0 aggregate rout of the Bavarians, striking twice in the return leg in Bavaria, before then keeping the capital club's Liga title hopes alive with a stunning injury-time equalizer in last weekend's 2-2 home draw with Valencia.
Ronaldo had been hoping to fire Carlo Ancelotti's men to a win at Valladolid that would draw them to within two points of Primera Division leader Atletico, with just two rounds remaining, but he lasted less than 10 minutes before hobbling off to be replaced by Alvaro Morata.
However, Ronaldo returned to the visitors' bench to watch the remainder of the game with his teammates, underlining that the injury was not as bad as first feared.