The Spaniard received eight minutes of treatment after an elbow from Cheikhou Kouyate, while the Argentine netted yet again for the Premier League champions in the first-half
Pellegrini admitted ahead of the game at the Etihad Stadium that he could be sacked if City fail to finish in the top four, with the reigning champions having lost four of their previous six top-flight matches.
|VIEW FROM ETIHAD STADIUM
|By Tom Maston
Question marks remain at Manchester City as to the suitability of Manuel Pellegrini as manager, but if they needed confidence then they will have come away with plenty following a comfortable victory over West Ham.
They were still not at their best, but with Sam Allardyce’s players showing all the intensity of a side whose season realistically ended six weeks ago, the hosts rarely needed to get out of second gear.
Jesus Navas was the star for the Premier League champions as he claimed two assists while Sergio Aguero and, for the first time in a while, Yaya Toure both proved their value with assured displays in the final third.
Jurgen Klopp may well have been watching with interest, and if he was then plenty will have impressed him about City. Despite that, they remain a long way behind the top teams in the division.
A bizarre 18th-minute own goal from James Collins put City ahead before Sergio Aguero doubled the lead with his 20th league goal of the campaign.
West Ham never threatened a fightback, but a routine victory was soured when Silva was caught by an elbow from Cheikhou Kouyate midway through the second half, with the Senegalese earning only a booking.
The former Valencia midfielder received lengthy treatment from the City medical team before being taken off on a stretcher.
City had the better of the opening stages as West Ham struggled to retain possession and, after Alexander Kolarov had gone close with a curling free-kick, the hosts took the lead through a huge stroke of fortune after 18 minutes.
Jesus Navas picked up the ball on the right wing following a poor goal kick from Adrian and the Spain international's cross was inadvertently turned home by Collins, whose attempted clearance looped over Adrian and in off the underside of the crossbar.
Collins did somewhat atone for that error as he produced a goal-saving tackle to prevent Silva from adding a second at the end of a well-worked City move.
West Ham grew into the game and provided a sporadic attacking threat, yet they were given a mountain to climb when Aguero finished off a sparkling counter-attack in the 36th minute.
Yaya Toure won the ball in midfield and set Aguero free, the Argentina striker then rounding off the attack with a clever low finish under Adrian after combining brilliantly with Navas.
Only an excellent last-ditch Carl Jenkinson tackle stopped Aguero from converting Toure's sublime reverse pass in the 49th minute as City continued to dominate after the restart.
Aguero spent a short time on the sidelines after seemingly picking up a knock in that tackle.
While Aguero recovered to make his way back onto the field, Silva was not so fortunate, the Spaniard receiving eight minutes of treatment on the field.
West Ham showed some positive intent in the time that remained, Enner Valencia and Kevin Nolan both spurning chances to pull one back late on.
But it is now one win in 11 league games for the visitors, while the attentions of a doubtlessly relieved Pellegrini will surely turn to the stricken Silva.