One player who settled his future before travelling across the Atlantic is Anthony Gordon, completing a move to Barcelona from Newcastle United last month.
But whether he will be joined in Catalonia by England team-mate Marcus Rashford is yet to be decided.
Barca have a deadline of 15 June – two days before England’s World Cup opener against Croatia – to activate a clause that will make the 28-year-old’s loan move from Manchester United permanent for £26m, but the Spanish club have been trying to renegotiate the terms.
There remains a possibility the deadline passes without agreement, leaving Rashford’s future unresolved and negotiations continuing during the tournament.
Defender John Stones, meanwhile, will be on the hunt for a new club after bringing an end to his decade-long spell at City.
During that time, he established himself as one of England’s most decorated players, winning six Premier League titles, the Champions League, two FA Cups and five League Cups among other honours.
“It’s about common sense. I would not like it [transfers] the day before a match, or on a matchday, that’s the policy,” said Tuchel.
“But everything else if it’s done privately, efficiently and quietly then we are always happy to help.
“It helps to have clarity around the player. The best thing we can have is clarity so if anyone has a chance to complete a change of club and a transfer we will not stand in their way.
“But it has to align, of course, with our schedule and our goals which is to be focused and prepared for matches.”