City have offered Sane a new contract, but Guardiola cast fresh doubt on the German international's future after his side thumped West Ham 4-1 in the Premier League Asia Trophy in Chinese city Nanjing.
"We want people to be happy to be here (at City). If he wants to stay we will be more than delighted and we are going to help him and everyone is going to help him," said Guardiola.
"We know his potential, we know his level, he's an incredible player.
"But at the same time I spoke to the club 10 times at the beginning here and said, I want people here to be happy to stay here, if they don't want (they can go).
"But the desire to have him here with us is always there."
Winger Sane has been strongly linked with a move to German champions Bayern and found himself frozen out at times last season.
Former Bayern boss Guardiola gave mixed messages about the future of the 23-year-old following the pre-season win over the Hammers.