SEVEN-TIME champion Michael Schumacher’s racing comeback is in serious doubt due to a six-month-old neck injury, his spokesperson admitted last night.<br /><br />Schumacher will only be allowed to come out of retirement at the European Grand Prix later this month if the 40-year-old passes a stringent medical assessment, she added.<br /><br />“It is not sure yet the neck will hold and the comeback can be started,” said Sabine Kehm.<br /><br />“It depends on medical investigations. Only after those will it be clear whether he will be able to drive.”<br /><br />The German has been tempted back to the track by former team Ferrari as a mid-season replacement for Felipe Massa, while the Brazilian recovers from a horror crash that fractured his skull at last month’s Hungarian Grand Prix.<br /><br />But Schumacher admitted earlier this week that his attempts to get race-fit almost three years after his retirement were being hampered by neck pain, caused by a motorbike accident he suffered in February.<br /><br />Kehm added: “From the very beginning it was made clear Michael would require medical checks. It is normal. Michael is fully geared up, and fully on it. He has been for a week now. But he is a human being, and we have to make sure everything is fine.”<br /><br />Schumacher said on Tuesday: “The practice is going pretty well. I only have to admit that my neck pinches a bit. We have to get a grip on that as my health is the priority – that’s the clear arrangement made with Ferrari and with my wife too.”<br /><br />The injury is the latest blow to Schumacher’s planned return at Valencia on 23 August. Ferrari this week slammed rivals Williams after they and two other teams blocked a request that Schumacher be allowed special dispensation to test this year’s car ahead of the race. Schumacher has so far only been able to practise in an older Ferrari F1 car.