The Hammers go to Old Trafford on Sunday to take on Jose Mourinho's Red Devils, the first of three consecutive away games while the IAAF World Championships take place at the London Stadium.
The East Londoners have made four signings this summer with Pablo Zabaleta and Joe Hart joining from Manchester City, Marko Arnautovic coming in for a club record £25 million and Javier Hernandez for a bargain £16m.
The team have not looked good or sharp in pre-season, though, being thumped by Manchester City 3-0 - a game where the Blues could easily have scored many more - and drawing 3-3 with German fourth tier side Altona in the last two matches.
West Ham's only win from six pre-season games came in a 2-1 triumph over Fulham.
But while pre-season is not about results, fans will be concerned more by the fact Bilic has made a somewhat bizarre admission on the club's official website that his players are still making the same mistakes as last season.
“You can’t make mistakes like those (against Manchester City), and to be fair we were making them last year, like when we played Man City at home when their first goal was similar," Bilic told whufc.com.
"After they score, it is then a big problem for you to turn the game around. When you don’t do those kind of mistakes, like for example against Spurs (a 1-0 win in May), then you have a chance. We did the mistake very early in the game and then it’s very difficult.”
For many Hammers fans it will be frustrating to hear Bilic admit his team are still making the same mistakes as last season.
As the manager he should be working to eradicate errors either through practice on the training pitch or by dropping and replacing the players who continue to make them.
If his team keeps making those errors when the season commences only one person will suffer the consequences, Bilic.