Boris Becker looks forward to the ATP World Tour Finals

skysports.com: From a player's point of view, how prestigious is this event?

skysports.com: Djokovic will again finish the year as World No 1. How tough is it to do that in successive years? BORIS: It's extremely difficult so it's a brilliant achievement by Novak. World rankings are very important for players - especially when it comes to the end of the year. Djokovic has put in a huge effort in the Fall to try and finish 2012 as the number one player in the world and he's succeeded. This is certainly a milestone in her career. skysports.com: Djokovic had such an incredible 2011, is it possible that he's improved this year? BORIS: It's very difficult to get to No 1 but it's much harder to sustain your form and defend that position because expectations are sky high. Djokovic may not have had as good a year as last year but he was still able to win important - and big - matches when it mattered. He won the Australian Open at the start of the year to add another Grand Slam to his tally, which all goes to show that he is one of the game's greats. skysports.com: We mustn't forget that Roger Federer is defending champion in London but at the age of 31 is his form starting to fade? BORIS: Well, he won Wimbledon this summer, which wasn't too shabby! You can never rule Federer out so long as he maintains the desire to be as competitive as he can be. But in the last couple of weeks he has lost a couple of matches that he wouldn't have lost in previous years, which has led to one or two people questioning whether he is as good as he was. But I think we're going to see the great Roger Federer in London because he wants to defend his title. skysports.com: Unfortunately Rafael Nadal won't be playing due to a knee injury. Is there a danger we won't see the best of him again? BORIS: We all should be worried because he's such a great ambassador for the game, not to mention a fantastic man. He's a true sportsman and competitor and tennis has really missed him when he's not been around. I hope that he gets better soon; we should remember that he's only 26 so time is still on his side. skysports.com: One man who has made a great recovery is Juan Martin del Potro. After winning in Vienna and Basel, could he spring a few surprises in London? BORIS: It's great to see him back. Having won the US Open in 2009, I thought he was going to be the next big thing but then he was injured for one year after that. Now he's back he's increasingly looking in good shape. Coming into the O2, I would definitely call him a dark horse. skysports.com: Outside of the top four, who do you most enjoy watching and why? BORIS: To be honest I like watching contrasting styles on the same court - I like to watch Tsonga against Murray, Del Potro against Djokovic, Ferrer against Federer. The best players trying to beat their opponent by trying to do the best that they can. That's what tennis at the O2 is all about - the best men in tennis fighting it out. It's a great exhibition - the eight players have already had a great year so they can relax a little bit and enjoy the moment because it's a privilege to be a part of it. skysports.com: This year's tournament is earlier than usual so there's no break between Paris and London. Is that a good idea if it gives players a longer break before the 2013 season? BORIS: I think it's a terrible idea - a big mistake, but it's not the players' fault. The ATP had no choice because of the Olympics and the Davis Cup; everything has been squeezed into a tighter schedule to give the players a longer break. But doing it this way isn't good for either tournament; Federer took the precautionary decision not to play Paris because he wants to be fit for London and the real danger with back-to-back tournaments is that it increases the likelihood of injury. skysports.com: Murray says he's in favour of more out-of-competition doping tests even though he thinks tennis is pretty clean. Is that a good idea? BORIS: I like the comment. It goes to show that the top tennis players feel very comfortable talking about issues like this. The recent events in cycling show that you should always be asking the question whether you think doping is going on or not. It's important that throughout the year, tennis players understand their responsibility and are prepared to undergo regular testing. skysports.com: Away from tennis, Boris, what do you like most about London in general? BORIS: London is a truly diverse international city - it's very cosmopolitan and is crammed full of different nationalities and cultures, which I find fascinating. It's also one of the secrets to the success of London as a sporting venue. Murray will be playing in front of his home crowd, but there will be plenty of support for the other players too from fans who love their tennis. skysports.com: I'm sure you'll have an eye on the Champions League this week. How do you think Bayern Munich will get on this season? BORIS: I support Bayern but also Chelsea, so last year's final was difficult for me! Winning away from home is always very important in the Champions League and Bayern did that at Lille the other week, but Group F is still looking very difficult. They are not through to the next stage by any means. skysports.com: Do you like what you've seen so far from the defending champions Chelsea? BORIS: I actually love the way they are playing this season. They are a very flamboyant side. They have great playmakers in midfield, which makes them fun to watch. But they were unfortunate against Shakhtar Donetsk and again against Manchester United in the Premier League last Sunday. I was at that match and they didn't deserve to lose. They still need a centre forward because I still have my doubts about whether Fernando Torres is the same player he used to be. Juan Mata and Oscar are both in great form, but your centre forward is the one who should score the majority of the goals and he's not doing that yet. There's a winter transfer window coming up soon and it would be nice if Chelsea could sign Radamal Falcao! Don't miss the 2012 ATP World Tour Finals, live from the O2, starting at 12pm on Monday Sky Sports 1 HD.