Toro Rosso team boss Franz Tost 'satisfied' with Ricciardo and Vergne so far in 2012

The duo replaced more experienced drivers Jaime Alguersuari and Sebastien Buemi at the Faenza-based squad for 2012 and have endured a mixed campaign so far.

Ricciardo, who made his grand prix debut with HRT last year, has scored two points from his ninth-place finish in the season-opening race in Australia. Vergne, making his debut in F1 this year, has meanwhile managed four.

Though the duo have not scored points since the second race of the season, Tost says both men are showing enough promise to leave him satisfied with their job.

"So far I must say that both of them are highly skilled and both of them, so far, have shown good performance," Tost told the official Formula 1 website.

"Daniel scored points in his first race for us in Melbourne, when he finished in P9 and Jean-Eric finished P8 Sepang, which showed that there is a lot of potential. The progress that both are making is quite promising, so I have to say that so far we are satisfied."

When asked if he was also satisfied with his drivers' development rate, he said: "Absolutely."

Tost is also hopeful his drivers will be able to enjoy a stronger second half of the season if the team can get its car to be more competitive.

"Both now have a bit more experience, they know the team better, the car better and the weekend procedure, so now I think it is up to us, the team, to provide them with a good car and make a step forward with new upgrades. Then I am convinced that we - hopefully - will have a successful second half of the season."

Tost, whose team's decision to drop Alguersuari and Buemi came as a surprise, denied he gives youngsters a hard time at the team, claiming some drivers simply do not work hard enough.

"Okay, let me put it this way, a driver has a hard time with me if he is not focused and if he is not finding the right-hand pedal. It is as easy as that. We push very hard and we do our best, but you know sometimes young drivers come into Formula 1 thinking that they've made it. And that's bullsh*t.

"To come into Formula 1 means that you are willing to start working very hard. Everything that you've done before is kindergarten (laughs). Being in Formula 1 you must live 365 days a year and 24 hours a day for Formula 1.

"And if I feel that one of our drivers doesn't do this then he runs into trouble. Then I give him trouble because either you are a professional or out you go. It is as simple as that."