He was tipped to be Barca's next big thing and even earned comparisons with Lionel Messi when he broke through in 2007 and although that never quite came to fruition he still boasts a glittering CV.
Boss Hughes said: "Anyone who knows European football will be aware of him as a player and the fact he sees his future at Stoke is really exciting and an endorsement of the club.
"He's desperate to prove himself in the Premier League and we're pleased to be able to offer him that platform.
"The time he spends in Germany with the squad will help him settle in and will give myself and the coaches the chance to take a good look at him."
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