Rat was a fans favourite at Upton Park but was told his contract would be paid up just minutes before the East Enders snapped up the impressive Pablo Armero from Napoli.
Armero has been first choice at the Italian club this season but the Hammers appear to have pulled off a coup to bring the full back to England.
The Colombian international, who is set to play at this summers’ World Cup, was in the stand as West Ham beat Swansea yesterday to edge them closer to the survival.
Rat is set to hold talks with Marseille today but the Romanian has plenty of options on the table after his surprising departure from the Premier League.
The left back has options in Italy, Spain and Turkey but is currently in France to thrash out a deal with Marseille as he is a free agent and can sign for a club whenever he wants now.