Harry Maguire lamented his horror miss against Milan on Thursday night before calling on Manchester United to "play a lot better" in the second leg at San Siro next week.
United were held to a 1-1 draw, with a late Simon Kjaer header cancelling out Amad Diallo's 50th-minute effort at Old Trafford.
Maguire had a great opportunity to put the hosts in charge before Diallo's opener, but somehow managed to hit the post from less than a yard out, and he took full responsibility for the poor finish post-match.
What's been said?
“I should have scored,” Maguire skipper told BT Sport. “I am not making any excuses for that one. I should have scored. I should have put it in the net.
"That’s why I am a defender and not a forward! But no excuses I have got to score.”
Maguire added on United's overall performance: “It is only halfway and we have to stay positive, but we need to play better.
“It is disappointing to concede in the last minute, especially at a set-play when we didn’t play well, we didn’t play at our best but were comfortable in the game.
“They didn’t create, they had a lot of possession after we scored the first goal but they didn’t create chances and it looked like we were going to see it out 1-0 and to concede the way we did, is really poor.
“We need to play better [in Italy] that what we have done tonight. I felt we did enough to win 1-0 although they probably had the majority of the game but we had the best chances of the game.
“But we need to play better and we know we can play better. It is going to be an exciting tie next Thursday and an important one for us. We have got to go there and play a lot better than we did tonight and we can go through.”
How did Maguire fail to score?
Alex Telles whipped in a corner from the right-hand side in the first half that Bruno Fernandes rose to flick toward the back post, with the ball subsequently looping over onrushing Milan goalkeeper Gianluigi Donnarumma and into the path of Maguire.
The towering centre-back appeared to have timed his run to perfection, but he struck the post from just a few feet away from the goal-line before ending up in the net himself, with the ball ultimately bouncing back out of danger.
Diallo came off the bench to initially spare Maguire's blushes with a stunning nodded finish early in the second period, but the England international's miss still ended up proving costly as Kjaer headed in a stoppage-time corner to give the Rossoneri a crucial away goal.
What's next?
Maguire will likely have the chance to atone for his error when the Red Devils welcome West Ham to Old Trafford on Sunday.
Ole Gunnar Solskjaer's men will head to Italy for the reverse fixture against Milan four days later, before their focus shifts to an FA Cup quarter-final showdown against Leicester City on March 21.