Jules Bianchi was missing in action at Sepang on Thursday.
Marussia let the Frenchman avoid the Malaysian heat by staying in his hotel, after calling in sick with a throat infection and fever, French television BFMTV and the sports daily L'Equipe reported.
Bianchi was, however, well enough to practice on Friday morning, completing 18 laps.
The Mexican had surgery over the winter, but Perez told correspondent Tobias Bruner he simply tweaked the knee whilst training, adding that it is "not a big issue".
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