BUDAPEST, Hungary - Ferrari's Fernando Alonso emerged as a possible surprise candidate for the vacant Red Bull seat on Sunday (July 28) after the Formula 1 world champions refused to rule him out.After Alonso's manager Luis Garcia Abad was seen entering the Red Bull motorhome at the 2013 Hungarian Grand Prix, speculation ran wild that he had entered the frame to replace Australian Mark Webber alongside World champion Sebastian Vettel in 2014.NEW BLOODAbad later assured reporters that he had talked to Red Bull principal Christian Horner about rising Spanish prospect and Red Bull young driver Carlos Sainz junior, son of the former World rally champion.But, in a paddock that thrives on intrigue, speculation inevitably followed despite Alonso being signed to Ferrari until the end of 2016 and Horner did nothing to nip it in the bud.Horner said when asked about Alonso: "We're in a fortunate position where there is quite a lot of interest in the seat for 2014."Any conversations between any other drivers or any other parties are always going to remain confidential," he said when it was pointed out that his words hardly constituted a denial."Of course there have been quite a few drivers who have expressed an interest in the seat, as you can imagine," said the Briton, who had spoken earlier in the weekend of some surprising approaches from inside and outside the paddock.'IS ALONSO AVAILABLE?'Asked whether Alonso was an option, he merely replied: "Is Alonso available? I don't know. You ask him?"Alonso has previously said he expects to see out his career at Ferrari, a team he has likened to a second family, but he has lost out to Vettel and Red Bull for three successive seasons and fell further behind after the 2013 Hungarian GP.While he is expected to stay at Ferrari, the speculation will not be unwelcome at Red Bull since it could have the double effect of sowing unease at their Italian rivals while also applying some pressure to Kimi Raikkonen.The Lotus driver is a leading candidate to partner Vettel, with young Australian Daniel Ricciardo the other recognised contender after impressing at Red Bull sister team Toro Rosso.The speculation might also be useful to Alonso in reminding Ferrari of his importance to them and the need to pull out all the stops to provide him with a winning car.Ferrari's team principal Stefano Domenicali, who was asked about Alonso's future subsequent to Horner's comments, shrugged at the speculation.Asked what he would say to the Spaniard - who turns 32 on Monday - to convince him to stay, the Italian smiled:"Happy birthday for tomorrow," he said. "No, I'm joking. It's about team work. We have to deliver a job. Full stop. This is the same for everyone, not only for him." Stay with Wheels24 for the 2013 Hungarian GP weekend.