He was on the sidelines for City's Champions League quarter-final first leg defeat to Tottenham Hotspur on Tuesday with a muscle injury.
He is improving but still touch and go for Sunday, Guardiola told reporters. "We will see today (Friday) and tomorrow."
Without the hard-working 24-year-old, City lacked potency in midfield against Spurs and now face an uphill task to reach the semi-finals.
"Bernardo Silva is an incredible player," Guardiola added.
"Playing wide he is a fighter. He's so intelligent and clever defensively. He knows when to cut back inside and with the ball, he can do anything."
In the league, City have 80 points, two points behind leaders Liverpool but with a game in hand.
(Reporting by Hardik Vyas in Bengaluru; editing by John Stonestreet)
