Milan attacker Zlatan Ibrahimovic is brimming with confidence ahead of this weekend's Serie A clash against Juventus, and the Swedish international has voiced his opinion that he is the best player in the world.The striker was quoted as saying by La Gazzetta dello Sport."I'm the best player in the world. I really feel that way. You're finished if you don't belief in yourself. The fact that I've never won the FIFA Player of the Year award or the Ballon d'Or doesn't mean that I can't be the best player."The striker also explained his decision to change clubs on a regular basis and pointed out that he needs a new challenge to stay fully motivated.He continued: "I feel that it's better not to stay at the same club too long. You keep learning new things if you change clubs every now and then. You can get complacent if you stick with the same club too long. You need to be motivated to perform and moving clubs forces you to prove your worth again time and time again."The former Barcelona and Inter attacker also talked about his future and revealed that he's likely to retire at the age of 33."Milan will probably be my last club. I expect to retire from professional football at the age of 33. I don't want to end my career spitting blood after every match simply because I'm too old to keep up."Source: Goal.com