Lewis Hamilton has admitted Mercedes may not have fixed the fault that has caused his engine to break down twice in the opening four rounds of the season. Ahead of this weekends Spanish GP, Mercedes have described finding a solution to the MGU-H failures which affected Hamiltons car in qualifying in both China and Russia as their highest priority.However, the world champions have been unable to offer Hamilton any guarantees that the problem - described by team boss Toto Wolff as a freak occurrence - will not occur again. The team have explained the issues we have had and the efforts they have made to rectify them, Hamilton told Sky Sports F1. They arent rectified but they are in the process of being rectified. Hopefully this weekend they will be rectified but that might not be the case. Trailing Nico Rosberg by 43 points in the standings, Hamilton has described the deficit as a mountain but insisted he is relishing challenge of trying to catch his team-mate. It is what it is, theres no point being concerned, he said. I have less engines than Nico, so Ive just got to do what l can with what l have. For sure, I have a mountain to climb, but l love a challenge and I am excited about it.Who is under the most pressure this weekend in Spain?The world champion has also vowed he has no concerns about his Mercedes garage crew after the teams decision to swap personnel over the winter coincided with a series of mechanical malfunctions on his car. The issues we have had are nothing to do with the mechanics, said Hamilton. That is not a concern. I have 100 per cent belief in the guys and the team. I am just hoping l have had my share of bad luck.While Hamilton has bore the brunt of Mercedes reliability glitches so far in 2016, Rosberg has reeled off four successive victories to establish a commanding early lead in the Drivers Championship.But, despite his run of wins from the final races of last season now stretching to seven, the German remains unmoved in his belief that nothing is won yet. Ted Kravitz thinks Mercedes have to sort out their mechanical problems at the Spanish GP if Lewis Hamilton is to have any chance of winning the drivers championship Its not difficult to keep the feet on the ground, you just need to look at reality, he said. Lewis is still the same Lewis as the last two years. Hes still just as quick and just as difficult to beat. Thats it.Its a long, long way to go.It wouldnt be good for me to think seven months down the road. The best way for me to try and win Barcelona is to think about Barcelona. And thats my aim, to win Barcelona. Thats the way I like to approach it and its the best approach for me.Rosberg led large parts of the 2014 season before Hamilton eventually overhauled him, but his championship advantage never exceeded 29 points. This time his lead is nearly the equivalent of two race victories but Rosberg, runner-up to Hamilton in each of the last two years, denied suggestions 2016 now presented him with an opportunity of a lifetime to become world champion. Fernando Alonso and Lewis Hamilton react to the news of Daniil Kvyat and Max Verstappens swap Im 30 now and still a young F1 age Id like think, he said. So I dont think that way and have such thoughts.Im just in a great situation which Im enjoying. I have the opportunity to win races - winning is a massive thrill and thats what I race for. [I am] up against some awesome drivers. Up against Lewis and the red guys, Kimi [Raikkonen] and Vettel. Some great battles and it makes it all the more fun when I win races, especially in a straight battle.Watch the Spanish GP live on Sky Sports F1. The race starts at 1pm on Sunday, with build-up underway at 11.30am. Or watch the race without a contract for £6.99 on NOW TV. Also See: When is the Spanish GP on Sky? Whats different on the cars in Barca? Paul George Shoes From China . After taking two big hits this week -- losing at home and dropping back-to-back games for the first time all season -- Indiana struck back by playing its most complete game of the year. Cheap Paul George Shoes . The parade and rally were held to celebrate the Saskatchewan Roughriders 45-23 win over the Hamilton Tiger-Cats on Sunday in the CFLs championship game. https://www.cheappaulgeorgeshoes.com/ . Perhaps Carroll was so prepared for a break because he believes there is very little the Seattle Seahawks need heading into the off-season. "I dont see anything that we need to add. We just have to get better," Carroll said. Clearance Paul George Shoes . Pirlo limped out of Sundays 1-0 win over Udinese after just 13 minutes. Juventus says Pirlo underwent tests on Monday which revealed he has "a second-degree lesion to the collateral medial ligament in his right knee. Paul George Shoes Deals .J. Ellis hit two-run homers and the NL West champion Los Angeles Dodgers defeated the San Diego Padres 4-0 Saturday night. Free-agent center fielder Ian Desmond rejected a one-year, $17.2 million qualifying offer from the Texas Rangers on Monday and instead will seeks a new contract on the open market.A year ago, Desmond turned down a qualifying offer from the Washington Nationals before settling for a one-year deal with Texas worth $8 million.The Rangers converted the former shortstop into an outfielder this past season, and he earned his second career AAll-Star selection.ddddddddddddHe finished with stats of? .285/.335/.446, 22 home runs, 86 RBIs and 21 stolen bases as the Rangers r