Manchester United boss Ole Gunnar Solskjaer believes Dean Henderson should have saved a last gasp header from Simon Kjaer against AC Milan.
The centre-half scored an equaliser for the Italian outfit against United at Old Trafford in the Europa League round of 16 first leg.
The game finished 1-1, after Amad Diallo had given United a lead early in the second half.
The Norwegian head coach told BT Sport post-match: "Very disappointed to concede with one of the last kicks of the ball, or head.
"That makes it harder of course, but it was always going to be going down to the second game there, anyway.
"I've seen him [Henderson] save them, but it's the structure that we lose. We dropped too deep and we get blocked off and they get the header on.
"We should have attacked the ball with the men we had there.
"We were a bit too slow with the possession. That's the learning we have to get into ourselves, we have to perform every single week.
"We're playing against good teams. Probably a draw is a fair result."
