The latest defeat, a 5-1 humiliation at the hands of London rivals Arsenal, set alarm bells ringing as the Hammers slipped one point and one place above the bottom three.
The club's summer transfer business has been the subject of scathing criticism from all quarters with only Edimilson Fernandes proving a success from the 10 first team players signed.
Under pressure: West Ham United manager Slaven Bilic
The Hammers have also thrown away more points from winning positions than any other team in the top flight which suggests their problem is putting teams away.
Despite their problems, though, West Ham co-owner Sullivan - who takes a lead on the running of the club and transfers - has admitted his surprise that one of them has actually come off sooner than expected in the shape of striker Ashley Fletcher.
West Ham co-owner David Sullivan
Speaking to the club's official website after Fletcher - who was initially earmarked to be farmed out on loan to Leeds - scored his first goal for the Hammers against his old club Manchester United last week, Sullivan gave an honest assessment.
"We identified Ashley as a big player for the future when we signed him during the summer, but he impressed in the opening part of the season and remains a key part of the squad," Sullivan told whufc.com.
West Ham United's Ashley Fletcher celebrates scoring his first goal
Sullivan and indeed Bilic will be hoping Fletcher's application and desire will rub off on other first team players after the former Croatia boss questioned the intensity of his players in training and games.
Fletcher has proved he can operate at the top level even if he is somewhat raw still.
But if he continues to show he is full of running and most importantly goal threat then Bilic will have no choice but to use him more regularly.