Luiz Razia has confirmed that off-track "conflicts" caused him to sit out last week's Barcelona test.
Despite intending to run its new Brazilian driver for two days in Spain, Marussia left Briton Max Chilton in the 2013 car for the entire test week, explaining only that it benefitted from the "consistency" of the amended schedule.
Rumours suggested 23-year-old Razia's sponsors had missed a payment date.
"In the contract," the driver told Folha de S.Paulo newspaper, "there are parties with responsibilities.
"We trust them, but we have some conflicts," Razia explained.
Asked if the "conflicts" were the reason he sat out Barcelona last week, he admitted: "Exactly.
"We did the right things, it's just that it's out of our control.
"We will solve it. We just need a few days."
Razia suggested Marussia's official explanation for the change of scheduling last week - that the team simply wanted Chilton to drive the whole test - was incorrect.
"I would not sign a contract with such a disadvantage," he insisted.
Folha de S.Paulo said a Marussia spokesperson did not return a phone call seeking comment.
