Tim Clement looks at Andy Murray's chances of defending his Maimi Masters title

Andy Murray faces the toughest of tasks in defending his Miami Masters title, coming up against a near full-strength field without form or a coach on his side.

The contenders (and Sky Bet odds) Novak Djokovic (7/4) The Serb has endured an uncharacteristically slow start to his campaign, suffering his first quarter-final exit in 15 Grand Slams at his most successful one, the Australian Open. Results have gradually improved since, losing to Federer in the Dubai semis before avenging that defeat two weeks later in California. It comes as no coincidence that a change of coaching set up has occurred at the same time and Vajda's absence here is a concern, with Becker yet to oversee a title. It might be suggested that the Indian Wells title paves over some worrying cracks still on display, with four of his matches going to three sets. Last year's defeat to Tommy Haas ended hopes of a third successive title here and a fourth in total, with the slower conditions normally perfectly complementing his game. Rafael Nadal (9/4) In the extraordinary career of the 'King of Clay', the start of this season has been somewhat of an anti-climax. The Spaniard battled rather than bulldozed his way to the Australian Open final before being struck by a back problem, while he also had to save match points against Pablo Andujar en route to a seemingly routine Rio Open title. Last week's third-round upset at the hands of Alexandr Dolgopolov was about as inexplicable as tennis results get, with Nadal previously enjoying conditions in Indian Wells more than any other hard court event and winning all five previous meetings with the Ukrainian in straight-sets. In contrast, he has never triumphed in Miami, losing finals in 2008 and 2011 but missed the last two instalments. The world No 1 is probably the main benefactor of the draw, with Milos Raonic now the top-ranked player in his quarter following Del Potro's withdrawal and Wawrinka seeded second in their half. Roger Federer (6/1) As aforementioned, Federer's results have greatly improved this year with his new racquet and coach having the desired effect. The Swiss star looks comfortable in his game again and it took some of Djokovic's best returning to end a 33-game unbroken streak in California. When able to stay aggressive, the Swiss star is playing as well as anyone on tour but Djokovic and Nadal have both been able to drag him down into baseline battles this year, from which there is only one outcome. Federer boasts a relatively modest record here, having failed to lift the trophy since back-to-back successes in 2005/06, while at 32 it remains to be seen whether going the distance in successive events will take a toll. Andy Murray (12/1) The disrupting influence of parting company with Lendl should not be underestimated given the importance of stability in such a mentally-demanding sport. Sky Bet reacted to the news by pushing the Scot out from 10/1 to 12/1 for the title, shorter than Wawrinka is to retain his Australian Open crown. The Scot is not currently considered in the same vein as Djokovic and Nadal, having bowed out of the last four events to players outside the top 10, despite claims that he is back to full fitness. If there's a place for Murray to regain his best form then it is at his second home in Miami. Whether he is mentally in the right place remains to be seen. Best of the rest Murray should arguably fall into this category at the same odds as and Wawrinka (201/) but we'll allow him some respect for rewriting the British tennis history books. Wawrinka has some way to go in doing the same for Swiss tennis and he is yet to win a single Masters title, while he went out at the same stage as the Scot in Indian Wells. Whether he can become a regular contender for the big titles at 28 is up for debate but the slower conditions here are unlikely to help. Likewise, Berdych (14/1) is a contender to go deep from the second quarter but cannot be touched without each-way cover, with Marin Cilic (33/1) and John Isner (50/1) making up a power-packed section. In Federer's quarter, Ferrer (40/1) is given little chance of going the distance again here as he returns from injury, while Grigor Dimitrov (50/1) has a good chance of a quarter-final run. Prediction In all honesty I was considering tipping up Murray with Lendl expected to be back in his corner and the conditions perfectly complimenting his game. However, with confidence the key to him returning to form further doubts surround his chances. Djokovic's coaching situation raises similar concerns but the Serb possesses greater mental resolve and, even if he continues to play below par, can grind it out in the slower conditions. Going on a 'horses for courses' logic, the winner will come from that fourth quarter. However, each-way options are apparent elsewhere, with Berdych a finalist here in 2010 and well rested following his early exit in Indian Wells. Best bets Novak Djokovic to win title - 13/8 Tomas Berdych each-way - 14/1 Trading Views Podcast Tim is joined by Sky Sports tennis pundit Barry Cowan to for a Miami Masters preview podcast. Listen here: