Defeat to PSV should provide Manchester United manager Louis van Gaal and his players with a big wake-up call, according to Dwight Yorke.
United led in the Netherlands after an impressive opening goal from Memphis Depay against his old club.
"I think they played well enough to certainly come away with a result," Yorke, who was part of United's 1999 treble-winning team, told Sky Sports.
"I am sure this will be a massive blow to the United players. This will probably be a wake-up call.
"To dominate the game for such a long period of time and to not have taken the opportunity and let PSV back into the game, they will be absolutely devastated.
"Call it naive but at this level you cannot afford to make the mistakes they have made and they paid the price. At this level of the competition you need to take your opportunities and they haven't been able to do that.
"United dominated from start to finish and with the ball possession stats I have in front of me they have done enough to come away with a point. To come away with nothing at all that will be a double blow along with losing Luke Shaw."
"If you look at Van Gaal's record at PSV it is not one that he is very proud of and that seems to have continued.
"Sometimes managers have that sort of record when they go to a certain stadium. Whatever they do they can't seem to come away with a result."
United return to action against Shaw's former club Southampton in the Premier League on Sunday.
