Merino has only been at Newcastle for a year after joining from Borussia Dortmund, and depsite impressing in his early appearances, it appears his time is already up at St James' Park.
He made 25 appearances for the 'Magpies' in a season disrupted by injuries, but Newcastle are ready to cash in.
The Basque midfielder has a release clause of around €11million, and it is believed that Sociedad will activate that. Merino will not train tomorrow, when all Newcastle players are expected to report for pre-season tests, as both sides want to get the move done quickly.
However, after signing Ki Sung-yeung last week, Newcastle already have a replacement should Merino leave, while Rafa Benitez is continuing to look at other targets.