The Frenchman had to be taken to hospital for a check-up last night as he suffered aches and pains all over his body - particularly in his elbow.
Simon has now allayed fears that Murray will be given a walkover, insisting that he will fight on.
"I will just try to go and take my chance, even if I don't have a lot of chance to win this one," said the 16th seed.
"But this is my job to go on the court and to do the maximum to bother him and to give him a hard time."
Simon's last victory over Murray came at the Rome Masters in 2007.