"Hopefully this week," he told Reuters, referring to the team's timeline for the announcement of Briton Max Chilton's 2013 teammate.
It was earlier strongly rumoured that Razia was en route to Jerez for the unveiling of the new MR02, but the latest whisper is that his sponsors are yet to pay the first instalment.
Booth denied that just because Razia is already talking about it, the deal is already done.
"That talking to the media is a dangerous thing, isn't it?" he smiled.
"Somebody put something on (the website) and it's fact straight away. We're talking to him."
Booth hinted, however, that another driver will be added to Marussia's Jerez test roster, because it's a "tough call" to expect rookie Chilton to bear the burden alone.
The other omens have also been ominious for Marussia ahead of 2013: the car launch featured only one driver, the livery features few sponsors, and Chilton crashed on Tuesday after a suspension failure.
It is also rumoured the former Virgin team is the only one in pitlane without a bilateral Concorde Agreement.
Booth, however, insisted: "I think our position favours us quite strongly. We are very compact and with a sound business plan.
"It's not an easy game to be in formula one. But we believe we have a sustainable business plan and we're comfortable with where we are."