West Ham lost 2-0 to Watford on Saturday afternoon.
Former West Ham wide man Trevor Sinclair has told BBC Sport that he felt the Hammers were complacent during their defeat to Watford.
West Ham went in to the game at Vicarage Road having beaten Chelsea 2-1 at Upton Park last week, and fans were certainly expecting another victory after a superb start to the campaign under new manager Slaven Bilic.
However, the Hammers struggled against Watford, and two goals from Odion Ighalo handed the Hornets a comfortable 2-0 victory, with James Collins' red card for West Ham compounding a torrid afternoon.
Having beaten Arsenal, Chelsea, Liverpool and Manchester City this season, fans are somewhat confused as to why West Ham have managed to lose to the likes of Bournemouth, Leicester and now Watford.
Now though, former West Ham midfielder Trevor Sinclair has told BBC Sport that he felt Bilic's side were too complacent against Watford.
"I looked at this game for West Ham and thought, sitting third in the table, they were expected to win it, but there has been a little bit of complacency," said Sinclair.
Now, West Ham face Everton at Upton Park on Saturday, and will be hoping to get back to winning ways - but they come up against a side who beat Sunderland 6-2 on Sunday.
The Hammers therefore can't afford to be complacent this time around, and need to focus even in games that aren't against the so-called 'big sides'.