Real Madrid sporting director Predrag Mijatovic has defended the club's acquisition of Arjen Robben, whose first five months at the Bernabeu since his move from Chelsea have been plagued by fitness setbacks.Robben joined Real last August for a fee believed to be more than £20million, but a series of injuries have severely limited the impact the Holland international has made in Spain. The 23-year-old winger, who also struggled with fitness problems at Chelsea, has started only five matches for Real. But Mijatovic said: 'He is only 23 and he has a lot of quality. This is not something that doesn't have a solution - we need him to relax a little, because it has not been easy mentally for him. 'It is too soon to say that we have made a mistake. We need more time. Robben will be very useful.'