Bernd Schuster says that Arjen Robben has been plagued by anxiety since his move to the Bernabeu.
The Dutch international has struggled to make an impact at Real Madrid since his £24million switch from Chelsea in the summer.
He has made only two starts in the league so far this season, and has struggled with a number of injuries. A muscle strain in his left leg is currently keeping him sidelined and forced him to play no part in Real's 2-0 victory over Osasuna on Sunday.
Real coach Schuster believes that Robben's attempts to justify the substantial investment the club made to bring him to Spain has increased the player's anxiety and affected his performances when given a chance.
"That's the problem we have with Robben, he wants to play and prove that he is ready," said the German coach.
"That anxiety has played against him. It's nothing serious, but we have to control it.
"He's had a couple of problems, but he is back in training and feels much better."
Robben's team-mate Guti believes that the player just needs time to establish himself within the squad, and that his confidence will grow the more opportunities he gets.
"The team is playing well, it is winning and it continues to lead the table, so it is difficult for him to get into the starting line-up," the Spanish international midfielder told AS.
"But he is going to have minutes that are going to give him confidence and allow him to demonstrate that he can play for Madrid."