Manuel Pellegrini believes the mental scars of a poor 2017-18 season are to blame for West Ham's concerning start to the new Premier League campaign.
Thumped 4-0 at Liverpool last weekend, the Hammers slumped to a second loss as Bournemouth overturned a half-time deficit to win 2-1 at London Stadium on Saturday.
The hosts were thoroughly outplayed in the second half with a creaking defence causing particular concern for Pellegrini just two games into his tenure.
The former Manchester City boss has identified a "lack of confidence" as the issue and admitted last season, much of which was spent fighting against relegation under David Moyes, is weighing on his players' minds.
"Yes, I think so. That's one of the reasons why in the second half we changed so much and tried to keep it 1-0," Pellegrini told reporters.
"I don't think it's the stadium and I don't think it's playing here. What they need is to try work for 90 minutes the way we did for 45 minutes today.
"We knew before we would need time with so many new players, management and style of play. Most of all we need to forget about last season.
"We need to recover the trust in each player and what they can do. We must recover the trust as a club and that's what we must do in the next week."
Bournemouth, in contrast, are enjoying a flying start after collecting a maximum six points from their opening two outings, having beaten Cardiff City 2-0 seven days earlier.
Callum Wilson sparked the latest victory with a splendid solo equaliser that earned praise from manager Eddie Howe.
"We really needed it, a really good goal," Howe told BBC Sport of the strike, which began with Wilson as the only Bournemouth player in the attacking half.
"He is outnumbered and showed his pace and it was a really good finish. Hopefully this is the start he needs to believe he can have a good season. We know he is capable.
"It was an excellent win and an excellent performance, especially the second half. At 1-0 down, there's a lot of work to do so credit to the players."