Sir Alex Ferguson has already seen off a few pretenders to his Manchester United throne - and he intends to repel a few more even though he will celebrate his 70th birthday later this year. It will be 25 years since Ferguson was appointed United manager on November 6. It is also nearly a decade since he performed an abrupt U-turn on his retirement plans. What has followed, in addition to five more Premier League titles and another Champions League triumph, has been a guessing game about when Ferguson will eventually call it a day. With that, comes the topic of his successor. At various times, Bryan Robson, Steve McClaren, Mark Hughes, Martin O'Neill and a host of top continental bosses have been linked with the job. Current favourite to replace Ferguson is Jose Mourinho, although a mounting disciplinary crime sheet at Real Madrid is not helping his cause. Yet, speaking to the Italian media at an awards ceremony at University of Rome Tor Vergata, Ferguson confirmed he is going nowhere. "Over the years I've had the question who do I think could replace me? Now in those years, some of the coaches they were talking about to replace me don't have jobs any more. "So it becomes very difficult because someone who I think has potential may be sacked by his club and disappear. "I think you would need someone very experienced in the long term. But I have absolutely no idea... first of all, I'm not retiring." With Arsene Wenger's crown slipping badly in recent times, Ferguson is unquestionably the most powerful manager in England. At United, his authority over team matters is absolute. It is impossible to imagine any player being bought or sold without his agreement, although he does not always get his man. "There's only one certainty: I will always be in charge. "I wanted Maldini. I asked his dad Cesare about Paolo and he told me I was crazy." One player he did bring in was Brazilian midfielder Anderson, who is starting to look more accomplished in the United midfield after a difficult settling-in process. "He has been tremendous," Ferguson told Inside United. "He's had a couple of long-term injuries which haven't helped him, but in the last year or so, he's steered clear of injury. "That means he's training every day so his fitness levels are much better. He is maturing so you can see the consistency in his game." With the transfer window closed, Ferguson must now get the best out of the players at his disposal, knowing he still has seven strikers to keep happy, including record signing Dimitar Berbatov, who has made a minimal contribution to United's 100% start to the campaign. He is not bothered about that though, content that he has never allowed disgruntled agents to exert more influence that the Scot feels is good for the club. "You cannot get rid of agents now - that is cast in stone because they are firmly rooted in the game," he said. "We have agents outside the gates of our academy waiting for the parents to come out from maybe 10, 11 years of age. "So what is required in the modern-day game are strong presidents and strong coaches that within their own structure accept the role of agents but not more than the role of the players."