Erik ten Hag was left frustrated by Manchester United's perceived lack of effort to score a second goal as they were held to a dramatic draw by Crystal Palace.
Bruno Fernandes had put United in control at half-time thanks to a well-worked opener just before the break.
For a while that looked set to be enough despite United – who seemed to commit fewer bodies forward in the second half – coming under pressure from Palace towards the end.
Eventually, a stunning Michael Olise free-kick found the top-right corner via the crossbar in the first minute of stoppage time, securing Palace a point and ending United's nine-match winning streak.
Ten Hag was disappointed by United's failed quest to get a second goal, which would have rendered Palace's late strike irrelevant.
"We dropped two points," he told BBC Sport. "When you're winning with two minutes to go... [Palace] don't create anything except one which was a corner and this one was a free-kick from far [out].
"You don't expect to drop points. We have to invest more to get that second goal and then not be in that situation that a lucky moment costs you two points.
"We were 1-0 up. In the second half we had a lot of space to kill them and go for the second. I never saw we really went for the second goal.
"It's difficult to say [why]. I have to criticise my team. Go for the second."
The late equaliser suddenly changed the complexion of Sunday's trip to Arsenal, which for a while on Wednesday looked to be shaping up as arguably the biggest game of the Premier League season so far.
Now, defeat at the Emirates Stadium will surely end any remaining dreams United have of winning the title this term as it would leave them 11 points adrift.
United will have to face the game without probably their most important player in Casemiro, who earned a late yellow card for a wild lunge on Wilfried Zaha after Fernandes pulled out of a challenge. But Ten Hag is refusing to panic.
"He's a really important player for us and a reason we're in this position," he said. "But last time we beat Arsenal without Casemiro. We need to do it again."
Goalkeeper David de Gea was even more frank about the loss of Casemiro and took the opportunity to vent about the fixture schedule, with Arsenal not in midweek action ahead of the Sunday showdown.
"It's a big blow to lose Casemiro for Sunday," told Sky Sports.
"I don't get it why Arsenal don't play as we have to play in the same week and they don't. Now we are missing one of our best players.
"I don't understand. Now we miss him for a big game and it is a big loss for us."