Marussia's 2012 car will not debut at the opening test of the official pre-season early next month.
It was rumoured on Monday that technical consultant Pat Symonds had said at the weekend that the former Virgin team's new single seater will appear only at the second February test, at Barcelona's Circuit de Catalunya.
The news has now been reported by France's L'Equipe.
Mercedes GP will also wait until Barcelona to debut its new car, the W03.
"We believe that the decision to run the car at the second winter test is the optimum compromise for our design and development programme," team boss Ross Brawn said last month.