West Ham isn't a team to undermine no doubt but I don't think they've shown enough strength that should make you think they'll be able to get a result against Arsenal at the Emirates stadium. Arsenal manager and players still believes that they stand a very good chance of catching up with Liverpool at the top of the English Premier League table and playing at home against a struggling West Ham side that are currently in the 16th position of the league table, I don't expect Arsenal to drop a single point in that game.
I don't think that anyone would want to underrate any team especially in the English premier league, but everyone is attributed respect according to what they do on the pitch and since David Moyes left westham they have really been a shadow of their old self.
There are currently on a run of loses and I don't think it will get better this weekend as I see them losing also, but this is football and anything can happen