Honest Shaw lays blame at players' feet for pathetic United effort
The defender's frank assessment came as Paul Pogba - the last to leave the United dressing-room at the London Stadium after the game - declined to speak to reporters.
When asked whether he wanted to stop and talk, the midfielder smiled, laughed and said: "You want me dead?"
Pogba's previous post-match remarks, when he questioned United's conservative tactics after the draw at home to Wolves the previous weekend, have caused friction with Mourinho, who stripped him of the vice-captaincy last week.
Pogba, who appears determined to leave United as soon as possible, was poor against West Ham and was substituted after 70 minutes.
The 3-1 defeat condemned United to their joint worst start after seven league games since 1989, with just 10 points and a negative goal difference.
Only David Moyes in 2013-14 fared as badly, and fresh questions are being raised as to whether Mourinho is able to turn it around and still has the support of his players.
United face Valencia in the Champions League at home tomorrow and then play Newcastle at Old Trafford next Saturday before the October international break.
Mourinho is struggling to settle on his best team or even his best formation and dropped Alexis Sanchez from his 18-man squad for the match against West Ham, even though the Chile international travelled to London.
West Ham manager Manuel Pellegrini said he was surprised and relieved to see his fellow Chilean left out.
Shaw was at fault as an early Felipe Anderson strike put West Ham ahead and United found themselves two down just before the break courtesy of a Victor Lindelof own goal.
Marcus Rashford's second-half reply briefly suggested a comeback was possible, but Marko Arnautovic soon restored the hosts' two-goal lead to secure a well-deserved win.
A lethargic, cumbersome United, playing an unfamiliar three-man defence, were second best for long spells, particularly in the first half, and speaking after the final whistle, Shaw admitted that they deserved to take nothing from the game.
"If you want the truth, I think it was honestly horrendous," he said. "We didn't look like a team today that was going to beat West Ham. I think individually and as a team we were awful.
"That's not good enough. It's hard to take and we're sorry to the fans for what they saw today. It just was not good enough from a Man United team with all the talent we have.
"From the first minute you could see we weren't winning the second balls and our duels. It's hard to take. That shouldn't be happening.
"Games like this we should be dominating, creating chances, showing people why we deserve to play for Man United and that didn't happen today. It was very poor from us."
Having also gone out of the League Cup last week, on penalties to Championship Derby County, United desperately need a positive result against Valencia to relieve the mounting pressure on Mourinho.
However Shaw said the responsibility lies with the players, adding: "We have to look at ourselves. We're the ones who go on the pitch. The manager isn't on the pitch, is he? You look at our team and we had a very strong team. No excuses."
Unless Mourinho can turn around the results and performances quickly it is difficult to see him surviving.
He will not resign, having signed a new contract earlier this year, but the club may be forced to act even though executive vice-chairman Ed Woodward wants to continue to back the Portuguese.
Nevertheless senior staff members are openly discussing whether Mourinho's reign as United manager is coming to an end and whether he has lost the ability to motivate the players.
The crisis comes as senior United sources dismissed as "nonsense" claims the club have approached Zinedine Zidane, who is understood to be interested in the job if it becomes available. (© Daily Telegraph, London)