Red Bull's leading team adviser, Helmut Marko, admits Daniel Ricciardo's impressive start to the formula one season has caught him by surprise.
The Australian has out-qualified and out-performed his teammate and defending champion Sebastian Vettel in three of the year's first four races.
If it weren't for his disqualification from the season opener in Melbourne in March, Ricciardo would be ahead of the four-time title winner on the overall driver standings heading into this weekend's Spanish Grand Prix.
''To be honest, he's surprising us,'' Marko, a long-time supporter of Vettel, told FoxSports.com. ''We knew he was quick, but being quick and using less tyres [than Vettel], and always being there, it doesn't matter what pressure.
And he's unlucky. In Bahrain, one more lap he would have been on the podium, in China two more laps he would have been on the podium. But he's always in a good mood and smiling.'' In April, Vettel conceded that Ricciardo was doing a better job at managing the team's new generation RB10 and he needed to step up his game.