The Black Cats have swooped to sign the likes of Adam Matthews, Sebastian Coates, Younes Kaboul and Jeremain Lens this summer, but manager Dick Advocaat now looks set to improve his midfield options.
The Sunderland Echo report that Fer, 25, is set to rubber stamp a season-long loan deal with Sunderland this week, with Advocaat poised to fend off interest from Premier League rivals West Ham as he looks to pair Fer with Lee Cattermole and Jack Rodwell in midfield.
Slaven Bilic's Hammers are searching for a midfielder given that last season's loan star Alex Song has returned to Barcelona, and Fer had been seen as an alternative to the former Arsenal ace.
However, the report states that Fer will instead join Sunderland in the coming days despite the late move from West Ham to lure him to Upton Park.
That will leave Bilic looking for another alternative to Song, unless he can tempt the Cameroonian midfielder back to Upton Park - which could well be a possibility given that the 27-year-old will have few first team opportunities at Barcelona this season.