Two-time world champion, Fernando Alonso, believes that the biggest threat he will face this season comes from Michael Schumacher.

The German gave the Spaniard a good run for his money in 2006, losing out on the title by thirteen points. After three years in retirement, the seven-time champion returned to the sport last season with Mercedes, though neither really impressed.

While some continue to write off the German, feeling that the sport has moved on since he retired and that at 42 he's too old anyway, Alonso is not one of them, fearing that the Mercedes driver remains a major threat.

"There will be five world champions on the track and the most dangerous champion for me is always Michael," he told reporters on the third day of his team's annual media event in the Italian Alps.

"Now in January if I have to choose one name I have to say Michael," he continued. "He is seven-times champion. He has nothing to prove. He had a difficult season but he is still a champion. He is still super class and if the car is right he will be a contender."

Asked about Sebastian Vettel, who claimed the title against all odds in the season finale in Abu Dhabi, Alonso replied: "Hopefully our car is better than the others and my toughest rival next year is Felipe. No doubt Sebastian will be a contender. He will have experience and will be calm in certain moments. He will drive better than last year and that makes him dangerous to us. McLaren will also be one of the favourites."

Referring to the 20-race calendar, the biggest in the sport's history. he said: "I like 20 races, I like racing, competing so to have more races is welcome. But I also like testing so I'd like 20 races and more testing. It's not easy and it's unfair for new drivers that they cannot test more."