The underperforming Scuderia Toro Rosso has confessed that the loss of Sebastian Vettel to 'parent' outfit Red Bull Racing this year has hit them harder than previously admitted - but hopes are high that replacement S?bastien Buemi will one day be able to emulate the German's success.

The small Faenza-based squad has endured a torrid opening half to the 2009 F1 campaign, with the STR4 proving to be significantly off the pace and inadequate funding being in place to sufficiently improve it [see separate story - click here].

Whilst the basic premise of the car appears to be the major problem, however, technical director Giorgio Ascanelli sought to point out that the driver inside the cockpit plays a considerable role too - and confirmed what many have long surmised in contending that much of the team's progress over the second part of 2008 was down to the influence of the man who delivered STR its breakthrough grand prix victory at Monza in September.

"The simple answer about the end of last year was that Vettel is a great driver," the Italian underlined. "Drivers are very important, and last year Vettel matured enormously, getting over the difficult phase every young driver has [of] not understanding why he was fast or slow. With a young and inexperienced driver like Buemi, when we do introduce changes, it is naturally harder for him to adapt to those changes."

Nonetheless, if Vettel was the undoubted star turn of last season for Toro Rosso, then it is clear that both Ascanelli and team principal Franz Tost see Buemi as possessing the necessary talent and potential to follow in the footsteps of the sport's youngest-ever grand prix-winner.

Should - as is hotly rumoured - reigning British F3 Champion Jaime Alguersuari get the nod to occupy the sister car in Hungary in place of the deposed S?bastien Bourdais, at the tender age of just 20 his Swiss team-mate will become the 'veteran' of the team and the man charged with the car's development. It is a role that both Ascanelli and Tost believe the former GP2 Series race-winner will handle with aplomb.

"To-date, he has taken part in just nine grands prix and in four of those he retired early," opined Ascanelli. "Add in the fact that there is no testing, and he is getting very little time in the car. When a young driver first comes into F1, he is like a daredevil, taking risks, but as his understanding increases and he suffers a few setbacks, it knocks his confidence which then has to be rebuilt.

"We cannot expect him to learn any faster - he is trying his best and doing a good job. Remember that when Vettel came to us, he had done one year as a third driver for BMW and had even taken part in one grand prix, but he could do no better than qualify 18th for us in his first race, in Hungary."

"Buemi has done a really good job so far," echoed Tost. "You have to consider that, as the only rookie on the grid this year, he is the first real victim of the in-season testing ban. He had therefore never driven at circuits like Silverstone or the N?rburgring in a Formula 1 car, which is completely different to tackling them in other types of car. While he knows the tracks from Formula 3 or GP2, it is not at all the same, because F1 is much more complex and little details - like how track conditions usually change from the third free practice session on Saturday morning to qualifying that same afternoon - are all part of the package that only comes with experience.

"Up until this year, we would have done a minimum of three days' testing at Silverstone for example, prior to the British Grand Prix, and at many other race venues - but you can't have everything, and while we are saving money through not testing, the downside is that young drivers will suffer. What we can say is that Buemi will be a much more complete driver for the 2010 season."