Sergio Agüero faces a lengthy layoff due to the knee ligament damage suffered during Saturday’s 1-0 win over Everton, though Manchester City are hopeful he will be out for no longer than a month in what still represents a sizeable blow to the champions.

The club is relieved Agüero has not suffered more serious damage after leaving the Etihad Stadium field in tears. The Argentinian has suffered distension of the lateral ligament of his left knee, according to reports in his homeland, with it being claimed the 19-goal striker could be ruled out for up to seven weeks.

With City travelling to Roma for Wednesday’s crucial Champions League game, Manuel Pellegrini has urged his team to win without Agüero but the Chilean now faces a striking crisis with Stevan Jovetic, who would normally start instead of Agüero, a doubt because of a hamstring problem while Edin Dzeko is not 100% fit following a calf injury.

Pellegrini is also uncertain of the fitness of Vincent Kompany, who will have a test in training after a hamstring strain, and David Silva following a knee problem.

Agüero suffered ligament damage after two minutes of the victory over Everton at the Etihad Stadium, the Argentinian leaving the field in tears. He is due to have a scan on Monday or Tuesday depending on when the swelling eases but City will be without their in-form striker for the final Group E match against Rudi García’s side.

City are level on points with Roma and CSKA Moscow and know that, if they beat the Italian club and the Russian champions do not defeat Bayern Munich, they are through to the knockout phase.

Pellegrini, the City manager, said: “We would prefer to play with Sergio but, if he cannot play, we must try to continue the same way we have been playing in the last week. Remember, last season we played a lot of games without Sergio – and these are the same players and the same team. So I hope we can recover from this important injury but we have a good squad and we will see how we can do it. He had pain in his knee. He told us he felt something strange happen inside. But we will know more soon.”

Pellegrini denied that City, who have won their last five matches, are a one-man side. “Well, I don’t know if that is the [correct] perception about us. It is one thing that a player can be in a very good moment as Sergio was until today but I don’t think he has carried us. We have beaten a very difficult team like Everton without Sergio, without Silva, without Kompany, without Jovetic and with Dzeko only able to play 20 minutes.

“Every big team must have important players like Sergio. I suppose Ronaldo is very important for Real Madrid, Messi is very important for Barcelona but neither of those teams are all about just one player. The confidence is very high in this moment for the whole team but the injuries mean it is not the best way to approach such an important game as Roma. But I have confidence in this team and I hope we will do it in the same way that we have won these last five games.”

Of Silva Pellegrini said: “We will see. I hope he is better, maybe he is not 100% but we have three more days to decide. Kompany – the same thing. He is running but we will see on Sunday and on Monday especially to see if he can play. Jovetic has a small problem in his hamstring. I hope he will be OK.”

Would Pellegrini risk Kompany against Roma if there was any doubt over his complete recovery? “I will take the decision with the player and the doctor,” he said, before explaining why José Pozo, who is 18, replaced Agüero on Saturday rather than Dzeko. “Because Pozo is a young player who has a lot of [physical] condition whereas Edin had only just trained with the squad today and was not able to play more than 20-25 minutes. It would have been a risk for the next game if we had made Edin play any more minutes. I think it was a good substitution. I think Pozo played very well. He had chances that were saved. So that was the reason.”

Fernandinho was not in the squad against Everton. “He had not recovered 100% from the last game. That is why I preferred to rest him today,” the manager added.