The Manchester City midfielder fell to the floor in pain and clutched his right ankle following a challenge with Morgan Amalfitano in the second half at the Etihad Stadium.
The Spain midfielder fell to the floor in pain and clutched his right ankle following a challenge with Morgan Amalfitano in the second half and was forced to leave the pitch on a stretcher with his foot in a protective boot.
"David Silva has a problem with his ankle, we’ll see tomorrow how important it is. He played in the last three games with some pain in his ankle, so tomorrow we’ll have news about it," Manuel Pellegrini told Sky Sports.
"The problem with David is that he played the last games with pain. I don’t know if that pain increased or if he has another problem where he twisted his ankle."
Silva was initially a doubt for the match after missing City's 2-2 draw with Sunderland last Wednesday due to a foot injury.
Sergio Aguero was substituted after just 64 minutes and was visibly limping towards the touchline before being replaced by Stevan Jovetic but Pellegrini maintains the Argentina international is not injured.
"Sergio, no, he doesn’t have any problems," said Pellegrini.
"I talked with him and 60 minutes was what he must play. Playing the way he was playing today, always running into the spaces, I think it’s important for him to recover and be 100 percent fit, giving him more minutes but not, at this moment, 90 minutes."
City raced into the lead against West Brom following strikes from Pablo Zabaleta and Aguero inside the opening 10 minutes. Graham Dorrans pulled a goal back for the visitors but Martin Demichelis netted from close range before the break to restore City's two-goal cushion.