Razia was confirmed as Timo Glock's replacement and the Brazilian will partner fellow rookie Max Chilton.
"For sure for the team it was a tough decision also, and for us it's going to be a tough job," he said of Marussia's decision to replace Glock with Razia.
"So I think we just need to get together and really work through all the difficulties we have and eventually come up with good stuff, good work and try to make the most of it."
"It's going to difficult for me and Chilton obviously because there's a lot of circuits we don't know and a lot of stuff is new to us, so we need to get on a rhythm. But eventually GP2 drivers, normally, get in a rhythm quite quick - so I hope so for myself as well."
Marussia's decision to partner Razia with Chilton means that it will be the sport's first all rookie line-up since HRT handed débuts to Karun Chandhok and Bruno Senna in 2010.
Although Razia acknowledges that he is behind his rivals in terms of acclimatisation, he believes dispelled the idea that problems could arise.
"We're going to have some tough times, but not problems," he said.
"I need to work hard to catch up with everybody", he added.
"It was a very hard winter for me because I had to keep my motivation to be training more than 17 hours a week and still being in contact with the teams to finally get an agreement."
"But it doesn't really matter any more now, the most important things are those that will bring me forward, and now this is what I'm going to focus on."
Razia, 2012's GP2 runner-up, completed 31 laps on his first day at work with Marussia but his running was cut short around midday.
"It was going quite good and then eventually we had a problem with the engine and we had to stop."