Sane has travelled with his team for City’s Champions League match at Basel
Sane was originally ruled out for up to seven weeks at the end of January after a late tackle from Cardiff defender Joe Bennett left the Germany winger with ligament damage.
However, the 22-year-old has travelled with City to Switzerland ahead of the first leg of their Champions League last-16 tie against Basel on Tuesday – five weeks ahead of schedule.
“I am surprised (he is fit),” said Guardiola. “He has worked very hard. He is not in perfect condition but he wants to help us.”
City have blazed a trail in this year’s Premier League and sit 16 points clear of closest challengers Manchester United while they sailed through the Champions League group stage.
They are among the frontrunners to go all the way in Europe’s elite club competition, but when asked whether his charges are ready to do so, Guardiola responded: “I don’t know but I have confidence in the guys.”
City have only once progressed beyond the last-16 in their last six attempts but captain Vincent Kompany believes they belong in the competition.
He said: “If there is a year, a moment when the club is ready to feel at home (in the Champions League) then it’s now.”
City remain in contention to complete an unprecedented clean sweep of Premier League, Champions League, FA Cup and League Cup honours but Kompany added: “Quadruple talk – none, but winning the next game and the next game – always.”