With the outfit's current supplier leaving the sport ahead of the new turbocharged V6 era next year, Webb has outlined Ferrari and Mercedes as the main power unit options, although Renault remains open to supplying an extra team on the grid.
"It is obvious that with the departure of Cosworth we can choose between Ferrari and Mercedes," Webb explained to Russia's Championat. "We are dealing with both and we will see what the options are.
"The price is also an important factor, because the cost of the engines in 2014 will be significantly higher than the current engines. We need to make sure that we choose the right partner and I hope to be able to make an announcement in the next four weeks."
Despite the fact that an engine supplier is yet to be confirmed, work on the team's 2014 car is progressing as planned and wind tunnel tests have recently taken place.
"The 2014 car is in the wind tunnel," added Webb. "Work on the design is in full progress; we already have a lot of information on the 2014 engines. But, of course, it would help to make a quick decision on the engine – preferably by the end of April."
Jules Bianchi, who joined Marussia as a race driver at the final pre-season test after Luiz Razia hit financial trouble, is a member of Ferrari's young driver program
03/28/13 (GMM) A backmarker and its young rookie are emerging as a true surprise package of 2013.
Still yet to sign a commercial deal with Bernie Ecclestone for the new season, it emerged recently that Marussia could have disappeared from the grid over the winter in ultimately failed merger talks with usual back-of-the-grid rival Caterham.
For 2013, the Banbury-based team signed up pay-drivers Max Chilton and Luiz Razia, but the latter Brazilian's sponsor money dried up before he could even travel to Melbourne.
At the eleventh hour, Marussia plumped instead for 23-year-old Frenchman Jules Bianchi; a handsome rookie with solid connections in the form of manager Nicolas Todt – son of the FIA president – and solidly under contract to Ferrari's driver development 'academy'.
The Ferrari link could see Marussia move from Cosworth to Maranello-made power for the new turbo V6 era.
"You have to ask the team (about that)," Bianchi told Switzerland's Motorsport Aktuell.
"I don't know anything about it," he added, despite admitting that Ferrari "helped me to get the cockpit".
Marussia might now be counting its lucky stars. Some believe that, after the first two races of 2013, and spotted from deep in the pack, Bianchi is standing out in the way that Fernando Alonso did at Minardi more than a decade ago.
So far, he is clearly faster than Briton Chilton – the son of wealthy insurance mogul Grahame Chilton – and arguably on the road to scoring the team's first-ever point.
"If I was a betting man," Marussia chief executive Andy Webb told Reuters on Thursday, "I would bet on us beating Caterham this season.
"I would also recommend placing a bet on Marussia scoring their first point this season," he added.
Bianchi agrees that the back end of the midfield is now a realistic target for Marussia, despite the team having the smallest budget in pitlane.
"Basically, the potential is there," Bianchi agreed. "For the team and for me.
"In qualifying in Malaysia we were only 3 tenths slower than Williams. Compared to last year they were two seconds faster than us. That's not bad, is it?"
Having tested extensively for Ferrari, and serving as Force India's Friday practice driver last year, Bianchi admitted he expected to be underwhelmed when he first stepped into the 2013 Marussia.
Actually, he was "surprised".
"I had expected the difference to be greater," said Bianchi.
"I believe that, if we continue like this, we can start to think about Q2, and if I keep dreaming then maybe even the first championship point."