Jose Mourinho admitted his players were caught in two minds as they surrendered their 100 per cent Champions League record.
United paid the price for missing a series of chances when Basel plundered an 89th-minute winner – to make Mourinho’s side wait to confirm their last 16 spot.
The goal denied United the point they needed to win Group A, although avoiding defeat at home to CSKA Moscow on December 5 will see them achieve that feat.
Mourinho conceded afterwards that his players did not know whether to go for the win or accept the draw that would see them through – and paid the price for that.
“The fact we knew one point was enough, probably we thought ‘now is not our time to try to win and time to control’, and in the end we lost,” said Mourinho.
“So it’s hard for me to be upset with the players. In the first-half the attitude was good, the football was good, so it’s really difficult to blame anyone.
“It’s just football – an easy match to win and then you lose. Great for them, because now they have a good chance to qualify.
“We lost because in the first half we should have been 5-0 or 6-0 up, but we couldn’t score one goal after being so dominant.”
United, Basel and CSKA Moscow could all end up on 12 points at the end of the group stage, if the Russian side win at Old Trafford and Basel beat Benfica.
But United would have to lose to CSKA by six goals not to go through, with even Mourinho admitting his brain had been scrambled by all the permutations.
“Can someone help me with the maths?” said Mourinho. “We don’t need to win the final match, we don’t even need to draw, it will come down to goals. But obviously we will try to win.”
United defender Daley Blind was beaten by Michael Lang at the far post for the last-gasp goal, but Mourinho refused to blame him.
“It’s not fair for Blind to blame himself,” said Mourinho. “He had a very positive game. We have to blame everyone on the pitch, because we had so many chances.”