Roberto Merhi has confirmed his F1 future is clouded beyond next weekend’s Spanish grand prix.
The rookie has only been racing for the resurrected Marussia team on the basis that he may be replaced at any time once a suitable ’pay driver’ is found.
So Merhi, 24, kicked off his Formula Renault 3.5 season in Spain at the weekend, admitting: "I have no idea of the future beyond the Spanish grand prix.
"So far I was the race driver, let’s see what happens next," he is quoted by El Confidencial.
McGregor-backed Giedo van der Garde’s manager has confirmed rumours that "contact" with Manor has taken place recently.
In Bahrain, Merhi was also substantially off the pace of his teammate Will Stevens, who is all signed up for the full season, thanks to his millions in backing.
But Merhi suggested there may be "differences" between the two red and white Manor cars.
"Yes, there are differences," he confirmed. "The cars are complete, but with some pieces from last year and perhaps mine is lacking something in comparison to the other."
Merhi also admits that some aspects of F1 have surprised him in 2015.
"Right now," he said, "it is as though there are four levels of formula one, four championships.
"There are a lot of differences between the engines, downforce, traction.
"You spend so much time in the race, and even practice, managing the (functions of the) steering wheel. It’s strange — it’s formula one, but then you are driving all the time without pushing the tyres too much."
Merhi said that, in contrast, his Formula Renault 3.5 "is a car that you can attack with more".
"Formula one has eight gears and many more horse power," he added, "but the cornering is practically equal, or even less."
The atmosphere in the paddock is also different in F1, Merhi explained: "(F1) people come in, do their job and then go home.
"It’s not like karting or other categories where everything is much more familiar. Some people treat it (F1) just as a job."