Doubts still remain over Razia
Marussia sporting director Graeme Lowdon has confirmed Luiz Razia is still contracted to the team.
The Banbury-based marque signed GP2 runner-up Razia earlier this month as replacement for Timo Glock, making no bones about the fact they needed the money more than an experienced driver.
Razia, however, has since run into difficulties with his sponsors who it is understood have been slow in coming forward with the cash.
It resulted in the 21-year-old sitting out last week's second pre-season test in Barcelona, with team-mate Max Chilton behind the wheel for all four days.
Although Razia expressed confidence he would be back in the cockpit for the final test that began on Thursday at the Circuit de Catalunya, it is unclear whether that was to be the case.
Asked about Razia's situation, Lowdon said: "We have a contract with Luiz. I'd prefer not to comment on the details of that contract, but as it currently stands there is no change.
"As part of a management team in F1 you have to make lots and lots of decisions that are right for the whole team.
"We've 200 employees, all of whom are focused on improving our performance. The driver is a key element of that, but it's only an element.
"So we have to do the right thing, put the right people in the car at the right time, and that's basically what you are seeing at the moment."
Speculation already has Heikki Kovalainen lined up for the seat if Razia's backers fail to come through, with the Finn out of work this year after losing his drive at Caterham.
Jules Bianchi has also been mentioned after missing out on a place at Force India to Adrian Sutil, and even Glock, although he is now contracted to drive for BMW in DTM, the German touring car series.
Lowdon, speaking on Sky Sports F1, said: "That (the speculation) is the nature of Formula One. It's filled with competitive people, and if you stand still in this game you go backwards.
"Speculation is completely understandable. It's not unusual to see it."
Marussia, meanwhile, are chasing a new engine partner for 2014 with Cosworth due to withdraw at the end of the current campaign.
After a four-year absence from Formula One, Cosworth returned at the start of 2010 when the sport welcomed three new teams in Virgin Racing (now Marussia), Lotus F1 Team (now Caterham) and HRT.
Cosworth supplied the trio, along with Williams who also signed up with the Northampton-based company.
Lotus, however, switched to Renault from 2011, as did Williams from the start of last year, and with HRT now defunct it leaves Marussia as Cosworth's only customer.
With the engine regulations due to change from next year, with teams running 1.6-litre turbo-charged V6 powerplants instead of 2.4-litre V8s, it would not be financially prudent for Cosworth to continue.
Lowdon said: "My understanding is Cosworth won't be making a 2014 engine.
"Obviously I don't work for Cosworth, but that is my understanding. The three suppliers will be Mercedes, Renault and Ferrari."