Record five-time Madrid Open winner Rafael Nadal pulled out of a media conference on Monday on the eve of his opening match at the tournament due to a stomach bug.
Eleven-time Roland Garros champion Nadal had also been suffering from the bug on Sunday, a week on from losing in the semi-final of the Barcelona Open.
The 17-time Grand Slam winner is racing to make up for lost time after failing to win a clay title so far this spring.
The second seed is due to open play in the second round against Canadian teenager Felix Auger-Aliassime.