Silva, who felt his hamstring tighten in the 2-1 win over United on Monday, will be given intensive treatment in a bid to be available for selection but Mancini believes the situation is touch and go at this stage.
“We will decide on Sunday morning on David,” he said.
“We don’t know if it’s possible for him to play or whether it might be a risk if he does. He has a chance, but I don’t think he can recover fully.
“He may be able to play some part, but we will make a final decision as late as possible.”
Mancini also dismissed his team will face a tired Chelsea at Wembley. Rafa Benitez’s side lost 3-2 to Rubin Kazan on Thursday afternoon but the City boss expects to face a much-changed starting XI in the semi-final.
“They will probably have three or four of the team that started the Europa League game but they rested the five or six players so they won’t be tired.
“Chelsea will be difficult and they are playing well at the moment so we know we will have to play our best to win this game.
“We are looking forward to the challenge and to playing at Wembley. This is a very important competition for us and we want to win it.”
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