Rondon, currently away with his nation Venezuela in the Copa America, is at the top of Rafa Benitez’s transfer priority list, if he stays on as manager at St James’s Park.
Villas-Boas was manager of Zenit when Rondon left for the Baggies in August 2015, a decision reportedly forced on the Portuguese boss when the Russian Football Union changed their rules to reduce the number of non-Russian players allowed on the field at any one time from seven to six.
According to a report in La Provence, Marseille want a deal done for the 29-year-old quickly.
Rondon scored 11 Premier League goals in 30 starts for United in 2018/19.
Miguel Almiron, meanwhile, was left in tears after Paraguay’s Copa America opener ended in a draw.
The United midfielder recovered from season-ending hamstring injury in time to make his country’s squad for the tournament, which is being staged in Brazil.
And Almiron, 25, starred as Paraguay took a 2-0 lead against Qatar in Rio de Janeiro, thanks to goals from Oscar Cardozo and Derlis Gonzalez, only to be pegged back by strikes from Almoez Ali and Boualem Khoukhi.
Almiron – who also created a goal for Cardozo which was ruled out by VAR – was in tears at the final whistle.