Bruno Senna will replace Nick Heidfeld in the Renault line-up at Sunday's Belgian Grand Prix, driving alongside Russia's Vitaly Petrov, the team announced on Wednesday.
"Lotus-Renault are happy to announce that Bruno Senna will race at the Belgian Grand Prix at Spa-Francorchamps this weekend," said a statement.
After 11 races this season, Heidfeld, who replaced the injured Robert Kubica, is eighth in the championship with 34 points, just ahead of Petrov on 32.
The team refused to explain why the experienced German had been dropped.
"Bruno will attend the official FIA press conference tomorrow (Thursday) at 15.00. A press release with further details on the matter will be issued tomorrow morning," said the Renault statement.