Sky Sports sources expect that Paul Robinson will complete his move from Blackburn to West Ham on Thursday.
It is understood that West Ham will also allow Stephen Henderson to move in the opposite direction and join Blackburn as part of the deal.
The move will see 33-year-old Robinson return to London where he spent four years with Tottenham before joining Rovers in 2008.
Henderson, 24, has made just two appearances for the Hammers since joining from Portsmouth in March last year.
He will be reunited with Michael Appleton who was his manager at Pompey.