Hamburg, Aug 5 (DPA) Michael Schumacher will make his planned Formula One comeback only if he gets the green light from doctors, his spokeswoman Sabine Kehm reiterated Wednesday.

The seven-times world championship Schumacher is set to drive a Ferrari car again as long as Felipe Massa recovers from head injuries sustained July 25 in a crash in qualifying for the Hungarian Grand Prix.

'Michael is working hard for his comeback but it was clear from the outset that this pends on the outcome of the medical examinations,' Kehm told the DPA.

Johannes Peil, whose team at the Bad Neuheim sports clinic has treated Schumacher for the last nine years, had also said on the weekend that Schumacher will only race again if he passes the medicals.

'We will only know if he can drive when all the tests have been concluded,' Peil told dpa.

Schumacher, 40, is working with Bad Nauheim doctors as he aims to race again three years after retirement, on August 23 at the European Grand Prix in Valencia, Spain.