Nemanja Vidic's injury is a huge blow for Manchester United and I think it could cost them their Premier League crown.Vidic is an essential part of United's team at both ends of the pitch and I just don't see them being strong enough to challenge for the title without him.He is their leader on the pitch, in many ways it would have been like taking Shaquille O'Neal out of the LA Lakers side and still expecting them to win the NBA finals. United will still perform, but you can't expect it to be at the same level as they would have done with Vidic in the team and I think that might ultimately prove to be the difference between them and their rivals, Manchester City.It hasn't been a good week for United all in all, and I doubt their fans would have thought things could get much worse after they got knocked out of the Champions League by Basel.United fans must have been looking at the game with optimism and many will have seen reaching the next round as a foregone conclusion.The real test for Sir Alex Ferguson and his squad will be how they do for the rest of the season. It's never easy for a club of that magnitude to not be involved in the biggest club competition in the world, but they will have to get over it, and quickly.Manchester City's week hasn't been much better, but they are five points clear at the top of the Premier League and look like champions in waiting. They'll qualify again and I'm certain they'll come back next year even stronger.They have Chelsea on Monday and a result in that match could put further distance between them and another title contender, and with their style of play they have the ability to do it.City play very entertaining football and defensively they are good, everyone knows their capabilities in attack and with David Silva being their X factor the sky is the limit for them.n n nThe surprises in the Champions League this week have led some people to question whether the Premier League is getting worse, which annoys me a little bit.Some teams win, some teams lose, that's what football is all about and people have to understand this. There were a lot of good teams that didn't qualify this week, Ajax are a perfect example.The Dutch side have a long tradition of playing and winning in Europe, and they are a good team, just because they didn't qualify this time around doesn't automatically mean that domestic football in Holland has got worse.If anything the other teams in Europe are getting better, no one would have thought that Basel would knock out United but that's why you play the games on the pitch, the game can be very cruel and very rewarding at the same time.n n nOne game I'll definitely be watching today is the first El Clasico of the season and I think it's going to be a fascinating enconter.Both Barcelona and Real Madrid are in good form, with Madrid top of La Liga and looking like the team to beat and Barca bouncing once again after a couple of surprising defeats.If that wasn't enough all three players shortlisted for the World Player of the Year award, Lionel Messi, Xavi and Christiano Ronaldo, will be on display and I think in both contests Messi is going to come out on top.Many would say that both the match and the award could go either way, but Messi is clearly the best player in the world. There hasn't been a player in the world in the least three years that has been close to him.He has won everything apart from the World Cup and that should be coming soon as well in his career. Xavi comes second to me, and Ronaldo comes third, but Messi should win it due to his consistency.