Jose Fonte apologised to West Ham's fans for the 3-0 defeat by Brighton which left a huge question mark over Slaven Bilic's future.
Hammers boss Bilic admitted his job could be on the line after a humiliating loss at home to the newly-promoted Seagulls.
But defender Fonte said the players must take responsibility and try to bounce back against Tottenham in the Carabao Cup on Wednesday.
"We are all disappointed, we are all frustrated and we apologise," Fonte told the club website.
"It was not the performance we wanted to produce and it wasn't the performance the fans deserve.
"We need to look at ourselves in the mirror because this cannot happen. It happened a few times last season and we have to put this right.
"We have got to move on. We have a game on Wednesday and we need to go and beat Spurs because we have to react, we have to bounce back."
The rot set in when Glenn Murray was left unmarked to nod in a Pascal Gross free-kick after just 10 minutes.
Jose Izquierdo curled in the second in first-half stoppage time and Murray finished West Ham off with a 75th-minute penalty.
While they were clinical in attack, Brighton also defended superbly with Shane Duffy and Lewis Dunk barely giving £16million Mexico striker Javier Hernandez a kick.
"There was a lot of pressure on us in the first half, but we defended well and scored at the right times, early on and just before half-time, which probably killed them a bit," Duffy told Brighton's website.
"It was still difficult with lots to do in terms of our positioning and defending crosses. Hernandez's movement is world class. You can't switch off, if you do he'll get a chance and he'll take it.
"They're three big points, and it's a big clean sheet. They had lost once at home, and it was a great performance from the lads.
"We've always believed that we can stay up. We're a hard team to beat and we've had a few new signings that have taken a while to settle in, but they're now doing brilliantly."