Romano claimed Guiu has undergone his medicals with the Blues in London.
He tweeted: “EXCL: Marc Guiu has completed medical tests as a new Chelsea player tonight in London!
“The release clause worth €6m has been paid, Barça have been informed with a formal document.
“Guiu signs as a new Chelsea player on a deal valid until June 2030.”
Barcelona offered Guiu a deal similar to that signed by academy talents Hector Fort and Marc Casado, but the teenager wants to continue his career in the Premier League.
Written by Ifreke Inyang