Manuel Pellegrini refused to single out goalkeeper Roberto as West Ham's miserable run continued with a 3-0 defeat at Burnley.
The Hammers are now without a win in seven games and have taken just two Premier League points in that time, their positive start to the campaign very much a thing of the past.
An injury suffered by first-choice keeper Lukasz Fabianski has not helped and Roberto will have nightmares about his afternoon at Turf Moor.
Ashley Barnes scored the opener from a corner and Roberto's ill-judged throw led to Dwight McNeil robbing Fabian Balbuena, who set up Chris Wood for the second.
The nadir came in the 54th minute when Roberto flapped at a corner from Ashley Westwood and only succeeded in pushing the ball into his own net.
He made a string of impressive saves thereafter but the damage was done.
Pellegrini had given Roberto a vote of confidence in his pre-match press conference but refused to comment on the keeper's performance after the game.
He said: "I feel that the team didn't play well, we lost 3-0 and the responsibility is with all of us," before adding: "Of course when the player is not in their best moment they worry about that but he has experience."
It was not just Roberto who was all at sea every time Burnley sent the ball into the box, and Pellegrini was left frustrated by his side's continued weakness from set-pieces.
He said: "I think it's difficult to analyse the performance when you concede such easy goals.
"It's one of the big problems that we are having. We conceded the first goal off a corner that was not a corner, it was a refereeing mistake, but we conceded one goal more off a set-piece.
"Of course that's very concerning. Newcastle was the same, Crystal Palace was the same. But after that I think we tried to continue playing the way we think is better but another mistake finished the game."
West Ham's miserable day was compounded by injuries to captain Mark Noble, who hobbled off early with a twisted ankle, and Manuel Lanzini, who was taken to hospital after lengthy treatment for a shoulder injury.
"We must see what the doctor says," added Pellegrini of Lanzini, who was given oxygen on the pitch. "It seems it's not so easy but we'll see how long he needs to recover."
West Ham will face Tottenham and Chelsea after the international break, and the Hammers boss said: "Of course when you have six or seven games without winning you must be concerned.
"You never know in this league which are the more difficult games and which are easy. As a team we will try to work harder. I hope in these 15 days we are going to work and we'll see what happens in the next game."
The emotions were very different for Burnley, who came into the game having lost their last three.
Manager Sean Dyche criticised his players following last weekend's 3-0 defeat by Sheffield United and could not have been happier with the response.
"Alter ego wasn't it?" he said. "Last week we weren't even close to a performance. I don't want to discredit Sheffield United, they were better than us, but we were a way off our mark.
"Today it came flooding back in, the edge that we play with, the organisation, the shape and the belief in the team."
Dyche, meanwhile, reasserted his belief in VAR despite Wood having another goal ruled out for a marginal offside.
"I'm still a fan of it," he said. "It's slow and the crowd are getting restless but if it's right, it's right, simple as that. We all know there's going to be strange ones and maybes, but the more right decisions over the season, (the better). It's got to be there."
