Manuel Pellegrini feels West Ham are still suffering with a hangover from last season.
Despite spending £100million on nine new signings over the summer, some familiar failings resurfaced as the Hammers slipped to a 2-1 defeat at home to Bournemouth.
They were leading through Marko Arnautovic’s first-half penalty but Callum Wilson’s solo goal and Steve Cook’s header condemed the hosts to a second straight defeat.
West Ham won only seven matches at the London Stadium last season and need their new faces to gel quickly if they are to avoid another torturous campaign.
“I was happy with the first 45 minutes but in the second half I felt the team did not trust trying to score another goal,” said Pellegrini.
“We made some mistakes with both goals, the first was one player against four of ours, and the second was a set-piece.
“First of all we need to forget last season and recover the trust of the club. Is last season still on their minds? Yes. That’s why in the second half we tried to keep it 1-0. It’s a lack of confidence.
“I don’t think they have fear to play here, what they need is to work the 90 minutes in the way we did the first 45 minutes.”
Pellegrini had reacted to last weekend’s 4-0 thumping at Liverpool by omitting Declan Rice, Michail Antonio and new signing Ryan Fredericks, none of whom were injured, from his squad.
Instead there was a surprise start for Robert Snodgrass, who was so far down the pecking order last season he spent most of it on loan at Aston Villa.
Javier Hernandez also got the nod in attack and it was the Mexican who won the penalty after Nathan Ake left a foot in as he cut inside.
Arnautovic stepped up ahead of regular penalty-taker Mark Noble and drilled a shot low past Asmir Begovic.
But the game turned on the hour mark when Wilson picked up the ball near the halfway line and begun to weave through West Ham.
The striker shrugged off challenges from Noble, Balbuena, Pablo Zabaleta and Angelo Ogbonna before rolling in his fifth goal in five appearances against the Hammers.
Five minutes later Ogbonna fouled David Brooks in the cormer and from Ryan Fraser’s free-kick, Cook stole in to thump a downward header past Lukasz Fabianski and make it two wins in two for Bournemouth.