Mourinho agreed, saying: "Exactly, (it) is a collective thing, the reason why we don't win is responsibility of everybody".
"Games like this [at West Ham] we should be dominating, creating chances, showing people why we deserve to play for Manchester United".
There will always be friction and debate after bad results, as there has been in Mourinho's two years and four months at the club, but now there is no debate: every United fan, without exception, can agree that this team has reached an irreparable crisis.
"I am sure they would start tomorrow by trying to beat us, so we have to be concentrated, focused".
Sanchez is also said to have made it clear to staff at United how angry and upset he was at his exclusion, although with no goals this season, he can hardly complain too much.
Pressure on Mourinho has been growing, with reports suggesting United are lining up Zinedine Zidane, who won three Champions League titles in a row with Real Madrid before surprisingly resigning, as his successor. "That's a private matter, I'm not going to answer to you".
"I still don't believe that a player is not honest".
Mata has scaled back his regular blog in the midst of a turbulent spell for the club as Mourinho prepares his team to face Valencia in the Champions League on Tuesday.
Few know Mourinho better than Matic, who followed the manager to Old Trafford having worked under him in good times and bad at Chelsea.
The Mirror, citing reports in Italy, says coach Unai Emery wants Napoli's Piotr Zielinski to replace the Wales worldwide.
Rio Ferdinand, the former Manchester United defender, says the club have "big decisions" to make in the coming weeks.
"I see different reactions, but sometimes what you see is different from the inside" I see some people on the outside look like they haven't lost a game, but in training they are working hard".
The 30-year-old was prevented from being asked about the feeling around this squad compared to the one that fell out with Mourinho towards the end of his second spell at Stamford Bridge.
United left-back Luke Shaw said the Hammers loss was "awful" and "horrendous" and that the players have to take responsibility.
"We are not scared to play".
United's 3-1 defeat at West Ham leaves them tenth on ten points - nine behind leaders Manchester City.
"If somebody tells them "I was a football player and I didn't give my best" then I change my opinion".