Poll: Which team is the biggest threat to Manchester United's title-defence

Singha All-Stars -- good thing they're not in the Premier League! Manchester City and Chelsea are, though. Which do you think poses a bigger threat to Manchester United this upcoming season for the Premier League title?

City, along with United and Chelsea, have a new manager in Manuel Pellegrini. While trophyless during his time as a manager in Europe, he is well-respected and he has an impressive record in the Champions League. Even though many of our noisy neighbours were sad to see the combative Roberto Mancini go, the former Real Madrid, Villarreal, and Malaga manager is likely to be an upgrade. His relatively relaxed attitude could potentially be a breath of fresh air in the City dressing room and he's undoubtedly a better tactician than his predecessor. The Chilean will also have the additions of Fernandinho and Jesus Navas to a squad that underachieved last year -- but it's one that is arguably as talented as anyone else's in England. In addition, it appears likely that they will be adding another talented striker before the summer transfer window ends.

Chelsea have brought in their former manager -- the special one the happy one. The two-time European Cup winner is arguably world football's greatest manager now that Sir Alex Ferguson has retired. Chelsea do have a few holes in their squad -- notably in central-midfield, at striker, and potentially at center-back -- but they boast extraordinary talent and talented youth. In addition, their attacking-midfielders are the envy of anyone in England and most of Europe. Furthermore, Jose Mourinho is likely to bring in more key players this summer.

Arsenal, Tottenham Hotspur, and Liverpool will all be difficult sides to play against this season, but none are likely to be genuine title-contenders. I've included them in the poll, though, just in case you fancy one of their chances.

Let us know who you think is the biggest threat to United's title-defense this season. Feel free to discuss it in the comments section below.