"I've said many times, it is not a regret," said City manager Guardiola. "He decides. He's doing really well. Congratulations, he's an exceptional player.

"He is a national team player with huge quality, doing really well in Dortmund. We wanted him to stay but he decided to leave, and when people decide to leave all we can do is (let them) leave.

"I wish him all the best, except when he plays against us. No regrets at all. If he's happy, I'm happy."

Sancho, who was 17 at the time and had not made a first-team appearance at City, was sold for £8million after rejecting the offer of a new contract at the Etihad Stadium.

He was reportedly valued at £108million by Dortmund when Manchester United were linked with a move for the player last summer.

Guardiola does not wonder what might have been.

"Nobody knows," he said. "Maybe he stays and we don't play good or better. The life of every person decides what life they lead.

"We will face him, try to control him. We know the quality he has, everyone knows. The quality in Dortmund is from all departments. They are a strong team."

Sancho is currently sidelined with a calf injury but is expected to be fit for the games against City on April 6 and 14.

He is, however, unavailable for England's upcoming internationals against San Marino, Albania and Portugal.

One player who will be involved is City defender John Stones, who has been recalled by England manager Gareth Southgate for the first time since October 2019.

That is just reward for his impressive form in quadruple-chasing City's fine season and Guardiola says the player deserves all the credit.

He said: "He deserves it for what he has done. I'm delighted, I'm so proud of him.

"Like Gareth said, us as managers have zero influence. The guys who play good consistently depend exclusively on them. John proved it.

"When you are focused and positive, happy to be for the most simple things, the results come. Congratulations, hopefully he can play good."