Managerial changes are part and parcel of the Barclays Premier League. There's a reason why that's become an old chestnut. Whether voluntary or enforced, the day youre hired, youre a day closer to the exit door, with few allowed to decide when their job is done.

This season has already seen Steve Bruce, Neil Warnock and Mick McCarthy handed their walking papers, but three months from now, those changes may seem but ripples in the pond. Seismic waves of change could occur at the top of the division over the next three months. It is not too much of a stretch of the imagination to think that the top six clubs in England could all have new managers come August. At Manchester City, Roberto Mancini seems safe enough, but should his expensively assembled squad not bring home the Premiership title or Europa League's crown, it wouldnt be surprising to see the Italian leaving Eastlands. Sheik Mansour has demonstrated that hes not afraid to make change, and given the intense scrutiny and player strife Mancini is constantly under, there's potential for a number of scenarios that could see club and manager part ways. With City having set the pace in England from the league's get go, his ambitious benefactors may not look kindly on losing the title to United.

Old Trafford has been a fortress for Sir Alex Ferguson over the last 25 years, part of the reason few would be surprised if the Red Devils again claimed the league. But what if the status quo persists? Is it possible that a trophyless season could be the undoing of the Scotsman? Getting bounced out of the UEFA Champions League in the group stages and losing in the FA Cup to Liverpool has already raised more than a few eyebrows. Ferguson cannot go on for ever, and like his counterpart at Eastlands, silverware is demanded. The Glazer family are bottom line people, and while a trophy-less season may not bring a full sea change, it will dust off the succession talk, if not the plans themselves. The loss United will surely incur this campaign will have them flirting with a cast of characters. How will Sir Alex react?

Harry Redknapp is the manager who is safest right now and under zero pressure from owners. In fact of all the top bosses, hes getting pressure to stay in North London; however, the call of the England job is one temptation that would be impossible to resist. Harry's saying the right things now, but once the season's over, Spurs are likely to be looking for a new boss. Its a completely different story on the other side of North London. Was Saturday the straw that broke the camel's back for Arsenal and Arsene Wenger? Especially coming on the heels of the most embarrassing loss in the club's long and storied European history? We're nearing the point where the Arsenal board will have no other option than to offer the Frenchman a golden handshake. It would certainly befit Wenger to leave on his on terms, but as weve seen in football many times before, there is no room for sentiment. No matter how many times the board say they have his back, results will ultimately determine his future. There's been no point under Wenger where that future's looked more bleak. Still, the silver lining in Wengers cloud is that his owner is not Roman Abramovich. The Russian oligarch wouldve canned the Professor five seasons ago, which leads me to believe that the incumbent on the Stamford Bridge hot seat has not got long to enjoy his position.

Andre Villas-Boas has got one match to save his job, and its on Tuesday night in one of the toughest stadiums in world football to get a result. The Stadio San Paolo is going to be rocking, and Napoli is a serious football team - hardly the venue you want for a Champions League round of 16 tie that will define your managerial career. With a rumored mutiny in the ranks, Villas-Boas has seemingly lost control of the team. Abramovich, despite his recent vote of confidence for the young manager, is going to be forced to act. Another man who also may be forced to act is Liverpool owner John W. Henry. A Carling Cup trophy next Sunday will certainly give Kenny Dalglish breathing room to continue his second coming, but a loss to Cardiff and an exit from the FA Cup will have the Red Sox owner going to the bullpen. There is a weird Millwall like vibe emanating from Anfield at the moment: No one likes us, we dont care. Is this really the Liverpool we know? Is it really the type of Liverpool FC that its American owners want to be projecting to their worldwide customer base? Dalglish is certainly the fulcrum of this image, and it could lead to his demise. Come the end of May, the Premier League's managerial carousel could be spinning at a rates never previously seen. Six big teams. Six huge managers. Potentially six stunning vacancies.