Fatigue and frustration reasons for Vettel struggles says Berger 14 May, 2014 Sebastian Vettel celebrates his first grand prix win at Monza with Toro Rosso team boss Gerhard Berger in 2008 Part of Sebastian Vettel’s struggle so far in 2014 is the fatigue factor after four consecutive world championship triumphs according to Gerhard Berger, a former Ferrari and McLaren driver wth close ties to Red Bull. Berger knows Vettel well, having given the German his first full-time Formula 1 seat in 2008 when a Toro Rosso co-owner.He was instrumental in the German’s first Formula 1 win with the Faenza based outfit.. So far in 2014, wearing the coveted number one on his Red Bull for the fourth consecutive time, Vettel has usually struggled even to match the pace of his fresh-faced new teammate Daniel Ricciardo. “You have to congratulate Ricciardo,” Austrian Berger told APA news agency. “He does an excellent job, and so consistently right from the start which is not something expected.” Behind Ricciardo’s shining performances, however, is a Vettel-factor, Berger argued. “We cannot forget that Vettel has won the championship four times; after four times with this pressure there is a certain fatigue that eventually makes its presence felt. “Four times you win everything,” Berger explained, “and then you get a car that you know you cannot win the race with due to engine performance. This is very hard to deal with. “Ricciardo is pleased about a podium but Vettel is not interested in third place; he wants to win the world championship,” he added. Red Bull and Vettel have upped their pace recently, but Berger doubts that Mercedes can be challenged this year – and he points the finger mainly at Renault. “Mercedes has had a great engine for years,” he said, “but Red Bull has been able to compensate with Vettel and the aerodynamics. “If Renault wants to catch up now, they will need to upgrade their budget and their people. We can’t forget about the resources that are behind Mercedes,” added Berger. (GMM) Subbed by AJN. Content on GrandPrix247.com by: staff & contributors, Reuters syndication, GMM service, Getty Images, Formula 1 teams, sponsors & organisations.