Manchester United take on West Ham in Saturday's 3 O' Clock kick-off in a Premier League fixture that is one of four in the space of a week-and-a-half as the busy Christmas schedule kicks up a gear. And the defending champions will go into those games - no disrespect to their opponents - knowing that anything less than a maximum return of 12 points will be considered a disaster. After this encounter with struggling West Ham, who are a point and a place above the relegation zone, the Red Devils travel to Hull and Norwich before entertaining crisis club Tottenham - must win games if their title defence is not to be written off before we've fully rang in the New Year. A run of crucial fixtures starts here, this afternoon, at home to a Hammers side who have won just two of their last 15 Premier League matches, losing eight of them. With the defence of their title slipping away from them, and even a top four finish looking iffy this season, United simply have to be winning games such as these. And here, we take a look at 5 Reasons Why It's Must Win For David Moyes. Click "Next" to get started.