SAKHIR, Bahrain - Formula 1 drivers Lewis Hamilton and Nico Rosberg say their relationship as team mates is likely to be tested in 2014 as they battle for the F1 title.They are already seen as front-runners for the championship, split the opening two races of the season and with Mercedes clearly dominant heading into the Bahrain GP.Hamilton and Rosberg get on better than many other team mates, having raced with and against each other since they were kids in karts.NO FRIENDS IN F1Rosberg said: "It has not changed at all. Maybe because we are not talking about the championship yet. There will be some tough times but I am sure we can get through them."Hamilton's relationship with Fernando Alonso was frosty when they were both racing for McLaren, then he had to battle for top-dog position with Jenson Button - demonstrations, he said, that showed the nature of F1 did not allow friendships.Hamilton said: "In F1 we can count our friends on one hand. Nico does not come in the five friends I have and I don't come in his."Team principal Toto Wolff said strategies to avoid track conflict had been discussed but acknowledged that even the best plans might not prevent trouble. "We have spent quite some time discussing those things, discussing scenarios and situations, but one day it will all be academic. We will run into controversy and we will run into a situation that we have to manage. "They are very competitive creatures."The Bahrain circuit will hold no surprises for Mercedes or any other team. It hosted extensive pre-season testing. The only potential wild card for this weekend is the introduction of night racing, the race to begin at 6pm local time on Sunday, as the sun sets.Red Bull driver Sebastian Vettel was the closest challenger to the Mercedes cars in Malaysia: "Mercedes is favourite. The quickest package, way quicker than us down the straight. It will be tricky for us."Stay with Wheels24 for the 2014 Bahrain F1 GP weekend.