Manquillo, 23, moves for an undisclosed fee and has signed a three-year contract.
Manchester City fans have been waiting for the next academy graduate to make an impact, and Phil Foden's performance offers hope it could be him.
Adam Lallana believes Liverpool have a chance of winning the Champions League if they can keep hold of their key players.
Arsenal have recovered from this week's stomach bug, with only Theo Walcott a doubt for Saturday's friendly against Chelsea in Beijing.
Conte said he had delivered news to Costa and in his agent in January after the striker was linked with a big-money move to China.
The way Mauricio Pochettino works is clear from the squad he has taken to America and the calibre of the opposition his Tottenham side will face.