The Baggies are struggling to conclude a deal for Leicester City's Jeff Schlupp.
The Baggies are said to have reached a stand-off in their pursuit of Leicester City's Jeff Schlupp, who it is claimed is considering handing in a transfer request at the King Power Stadium.
The report claims Tony Pulis' team are also keen on Newcastle United's Paul Dummett in addition to Charlie Taylor of Leeds United.
Borthwick-Jackson's name is a new one, however, and is perhaps an attainable option having been left out of both United's two competitive fixtures this season.
The teenage Mancunian burst onto the scene last season, with the Red Devils in the midst of on an injury crisis, and made 14 appearances in total.
However, the appointment of Jose Mourinho as manager, combined with Luke Shaw's return from a broken leg, has left Borthwick-Jackson out of the first-team picture as things stand.
West Brom are desperately short of natural left-back options, with Sebastien Pocognoli not fancied by Pulis, who often chose to deploy centre-backs or left-wingers there last season.