Former Marussia driver Timo Glock believes the team will struggle with an all-rookie line-up in 2013.
Glock raced for the team between 2010 and 2012 but stood aside in order for Marussia to sign Luiz Razia, who comes with financial backing.
Marussia will field Razia alongside Max Chilton, meaning that the GP2 graduates will form the first all rookie line-up since HRT in 2010.
"It's definitely not going to be easy for them, especially in testing, where you need to be able to make the right decisions in pinpointing the weaknesses of the car," Glock told Autosport.
"That's something that only comes from experience."
"There's a lot of pressure on Luiz and Max to get up to speed with the car quickly."
"That's the critical part; knowing that perhaps the simulation you have brought to a track isn't quite accurate and being able to make a forward step from there."
Glock pinpoints money as the key reason why Marussia is currently unable to make sufficient progress.
"Generally they just need to find a way of getting more financial support so that they can move forwards and develop. The bigger teams won't stop developing and that's what makes it so hard for the smaller teams to catch up. The bigger teams bring updates to every race while the smaller teams have updates maybe every five or six races."
"At least they've definitely moved forward with the car. It's quicker this year. It's all about developing, about how they get on with KERS."
Glock will race for BMW in the DTM series this season.
