The City captain was substituted at half-time during Saturday’s dramatic 2-1 win over Southampton.
And speaking at his post-match press conference, Guardiola revealed that Silva had been replaced after reporting a ‘muscular problem’.
The City boss added that he expected the Spanish midfielder to be out of action for '10 to 12 days.'.
“Five minutes before half-time David told me he had little problem muscular,” Guardiola confirmed
“(Will he be OK for Atalanta and Liverpool?) I don’t think so.
“I didn’t speak with the doctor but when he has some muscular problems and cannot play more minutes it’s because he has something, and muscular problems normally means 10 to 12 days (out).”
It’s the start of another big week for the Club, with City knowing that a victory in Italy would secure our passage through to the last 16 of the Champions League.
A first league win at Liverpool since 2003 meanwhile would reduce the gap at the top of the Premier League to just three points.
But quizzed as to whether he would seek to prioritise the game at Anfield, Guardiola’s response was unequivocal.
“Do you think we can four titles in one season by prioritising games?” the City manager responded.
“No. We are going to play with the best team as possible to win in Italy against Atalanta and after that Anfield.
“Nobody can assure me don’t do what you have to do at Atalanta to make a better performance against Liverpool.
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“The best way to face Atalanta is the way we played against Southampton.
“And the best way to play at Anfield is to go to Atalanta who in the last two seasons have been fighting with the tops clubs in Italy.
“They can score four, five six goals every game.
“We are going to play with the best team considering the regeneration, the opponent, the way they play and try to make a good performance and qualify for the next stages in February.”