Formula 1 world champion Lewis Hamilton believes that Fernando Alonso and Daniel Ricciardo could pose a threat as he looks to defend his title in 2015.

The Briton's only meaningful competition for the 2014 crown came in the form of Mercedes teammate Nico Rosberg, who finished 67 points behind in the standings.

However, Hamilton has suggested that Red Bull's Ricciardo could be a possible challenger for glory next season, while the 29-year-old is intrigued by the prospect of Fernando Alonso racing for McLaren.

He told reporters: "The good thing about this period of time in Formula 1 is that when I won the championship in 2008, the following year we had a year like this with some new rules and regulations and as a team we didn't do a good job to adapt to that, so I didn't have a chance to fight to keep my championship.

"Next year will be an evolution of this year's car so I'm hoping that we'll be at least able to fight. Nico's going to come back stronger and I'll have to make sure I come back even stronger to stay ahead of him.

"You know Daniel Ricciardo has been doing an amazing job, it will be interesting to see what Fernando does in his car. It's very difficult to know but I don't particularly care who's behind! You don't care do you? You just want to look ahead!"

Mercedes won the constructors' championship by 306 points from Red Bull.