Red Bull chief Christian Horner on Saturday backed Mark Webber to step out of world champion Sebastian Vettel\'s shadow in the new Formula One season. Australian Webber had to wait until the final race in Brazil to register his first and only win of the 2011 campaign and finished third in the standings behind Jenson Button in a McLaren. But Horner believes Webber will mount a stronger challenge in 2012. \"Mark has been with the team for five seasons now and he\'s a very valued member for the team,\" Horner told www.autosport.com. \"He\'s training hard, his motivation seems very high and I\'m sure he\'s going to be fully focused on having a very strong 2012.\" Horner added that it was still too early to back either young Australian Daniel Ricciardo or French rookie Jean-Eric Vergne, who will drive for Red Bull\'s sister team Torro Rosso in 2012, as potential successors to Webber alongside Vettel. \"Those two guys are both very competitive,\" said the Red Bull team principal. \"They are products of the Red Bull junior programme and are both Red Bull Racing drivers on loan to Toro Rosso to develop them. \"Time will tell. There are no guarantees. It\'s the best way to see how their talent evolves over the next season or so.\" Ricciardo, who featured for part of the 2011 season with HRT, and Vergne have replaced Sebastien Buemi and Jaime Alguersuari.