Despite a Europa League and EFL Cup double, much is expected from Jose Mourinho's side this term after a disappointing sixth-placed finish in the top flight of English football last season.
Manchester United's Romelu Lukaku celebrates scoring his side's second goal of the game during the Premier League match at Old Trafford, Manchester. Last campaign was full of too many inconsistences and Bilic will know he needs to start picking up points fast if he wants to prevent the exit rumours circulating once more.
The Premier League match between Manchester United and West Ham will be broadcast live online and on NBCSN.
Mata was through again shortly after following a lovely looped pass over the top by Pogba, but the Spaniard's square pass for Lukaku at the far post was cut out. However, the Red Devils will have to move forward and will have to depend on the likes of Paul Pogba, Romelu Lukaku, Mkhitaryan and others to fetch them points.
He could have had a third but for Zabaleta's timely block on the hour mark and Rashford came close to a deserved goal, striking the foot of the post with a teasing effort from the left flank. United take a free-kick quickly and slip Mata in.
But there there was to be yet more Manchester misery for West Ham in the final three minutes as Mkhitaryan invited Martial to race behind the visitors' defence and calmly slot past the helplessly exposed Hart. Then, after being central to much of United's pretty play, Pogba made a decision to go it alone, carrying the ball forward unchallenged before angling a shot past Hart.