Bad Nauheim/Hamburg - Michael Schumacher's planned comeback to Formula One for this month's European Grand Prix in Valencia is putting pressure on his doctors to ensure the Ferrari driver is fit enough to deal with the rigours of the sport.

"It's an exceptional situation for us because nobody had planned with preparing such an intensive training programme," Dr Johannes Peil, whose team at the Bad Neuheim sports clinic has treated Schumacher for the last nine years, told German Press Agency dpa.

Normally a driver has months to get in shape but the 40-year-old Schumacher only has three weeks until the race in Valencia on August 23, when he will replace the injured Felipe Massa in the Ferrari cockpit.

"We have an emergency programme in place until Valencia, after which time a standard one will come into operation. Everything is important but we only have a limited time to complete everything," he said.

"It's only because Michael has done so much in his sport since he retired is a return even possible. Even after a break of three or four weeks, a Formula One driver needs some time to adapt correctly to the extreme pressures.

"It affects the spinal chord as well as the lower arms and hands. No training is a substitute for the experience of driving in a racing car."

Schumacher's fitness programme involves up to four physiotherapy sessions a day as well as endurance and other exercises designed specifically for F1 drivers.

"We will be working with two physiotherapists over the next two or three weeks to ensure we can achieve all our tasks," said Peil.

While Schumacher is well-known as a fitness fanatic, Peil said there would be no chance that the seven-time world champion could overdo his preparations this time around.

"We won't have to hold him back this time as the challenges are so numerous and the time so short," said Peil, who added that he noticed Schumacher's huge desire to make this comeback a success.

"It gives us hope that we will achieve the results we need in order for him to race. He wants to make it. Schumacher's complete professionalism stands behind this preparation."

Peil refused to comment specifically on the neck injury Schumacher picked up in February when he fell off a motorbike, saying only that "all injuries" a driver has picked up in his career would have to be taken into account.

"We try our best to balance things accordingly. But we will only know if he can drive when all the tests have been concluded," said Peil.(dpa)