Michael Schumacher conceded that his chances of winning a sixth straight drivers' title look slim after Ferrari's poor start to the season.
Schumacher, who was seventh in Sunday's Malaysian Grand Prix, said: "We are simply not strong enough in several areas at the moment."
"If after five or six races we are still struggling then we won't have to bother talking about the championship."
Team boss Jean Todt said Ferrari had "no excuses after a race like this".
Ferrari have started the season with an updated version of their 2004 car after delaying the production of their new car to ensure it is as fast as possible.
Schumacher is to test the new F2005 this week as the team try towork out whether it is ready to make its debut at the next race in Bahrain in two weeks' time.
Schumacher said: "I head to Mugello to drive the F2005 for the first time and I am looking forward to that.
"Clearly we would love to have the new car, given the situation. It's obviously faster but if it's not ready, it's not ready. Personally I think it will be very tight."
Ferrari trail runaway leaders Renault by 16 points in the constructors championship after just two races, while Schumacher is 15 points off Alonso's total.
"There is no question at the moment the gap with Renault is very big," added Schumacher.
"I can see how it's hard to understand how we won 15 races last season and coming here we are fighting for seventh.
"I don't expect a giant leap in Bahrain, but it's clear we must improve.
"It's extremely wrong to blame just one factor. We must analyse this race and take it step by step.
"But we have the competence to come back and I do think we will win races this year. It will be difficult but after two races you can't say it's hopeless."
Williams' Nick Heidfeld - who equalled his best placing by finishing third in Malaysia - said: "At the moment Ferrari are struggling. They're not used to it and it will be interesting to see how they handle it."