Some teams are pushing for next week's Barcelona test to become a five-day schedule.
The rumours had already emerged this week at Jerez, where poor weather has affected two of the four days of running so far at the penultimate test of the winter.
Barcelona is currently a four-day schedule set to run from next Thursday through Sunday.
The Dutch website f1today.nl reports that moves are afoot to extend the test by one day.
Sauber's Pedro de la Rosa has been quoted as saying he doubts the teams will agree, because total unanimity - including the consent of Campos and USF1 - is required.
"We have heard the rumours but there has been no official contact," said a spokesman at the Circuit de Catalunya.
"It will not be on March 1 because there will be other racing at our circuit. The only possibility is therefore (Wednesday) February 24, which is a filming day for Red Bull Racing," the track representative added.