As per the Daily Mail, ESPN, and the Beeb. Now backed up by AS. The Beeb says that it will be a year long loan move but with a view to making it a permanent deal. An announcement is expected early next week but there are reports that Sahin is already in London.
Jose Mourinho's first choice was Liverpool because of his past association with Brendan Rodgers who coached Chelsea's reserve side while he was there. But Sahin's personal preference was Arsenal and the chance of playing in the Champions League. Which in the end, the Merengues had to respect.