Red Bull team principal Christian Horner has named Jenson Button as the biggest threat to Red Bull's bid for a third successive Formula One crown.
When asked who he thought could challenge their dominance, Horner quipped “Probably Jenson.” However, Horner stopped short of saying that the British driver will oust the current constructors' champions, warning that the double world champion Sebastian Vettel will be better than last year.
We are yet to see the best from him. He will evolve and get stronger,” Horner told BBC Radio 5 Live, when asked about Vettel.
However, following three separate weeks of winter testing, McLaren appear stronger than twelve months ago, when the team lacked pace and failed to keep up with the flying start of Red Bull.
It took the British team a majority of the season to catch up with Horner's team, with 2009 world champion Jenson Button eventually finishing the season in second place, a massive 122 points behind Vettel.
When asked who else he thought could pose a threat to Red Bull this year, Horner named Lewis Hamilton, Fernando Alonso and Kimi Raikkonen.
"Seb had an unbelievable year and in the end dominated significantly,but there are some big opponents out there, with six world champions on the grid," he continued.
"Lewis is going to be pushing hard this year, Jenson had a great year last year, you can't rule out Fernando because he is a world-class driver and it will be interesting to see how Kimi fares on his return."
Horner declared that he was pleased with the performance of the RB8 in pre-season testing, confirming that the upgrade package used in Barcelona would be on the car for the opening race of the 2012 season.
Those upgrades seem to be working OK and will certainly be on the car in Australia in 10 days' time," he said.
"I think we're set for a really fascinating season. Things move on so quickly and the running order at the end of last year doesn't guarantee it's going to be the running order at beginning of this year."