Ole Gunnar Solskjaer has picked out a second Manchester United weakness following their 1-0 defeat to West Ham on Wednesday.
The Red Devils crashed out of the League Cup after Manuel Lanzini's ninth-minute strike gave David Moyes ' men the win.
Prior to the match, Solskjaer vowed that his team must improve in a defensive sense - only to be cut open on multiple occasions during the tie.
Not only that but the Norwegian has admitted United struggle when facing a "low block," put in more traditional terms, the opposition sitting deep and denying space in behind.
Spearheaded by the largely anonymous Anthony Martial, the Red Devils' attack struggled to penetrate the Irons' rear guard which prompted Solskjaer to admit his side's shortcomings.
Solskjaer admitted Man Utd's shortcomings in their defeat to Moyes' men ( Image:
Action Images via Reuters)
"We're not great when we play against a low block and just sling crosses in because we're not that type of team," the United boss admitted. "We didn't have those types of players."
"So we tried to play around them, through them, get in behind them, but we didn't create enough big chances to score."
Solskjaer's comments regarding his team's defensive lapses followed their 2-1 win at West Ham in the Premier League on Sunday.
Ex-Irons loanee Jesse Lingard scored in the 89th minute to give the Red Devils a late lead, before David De Gea saved a penalty from Mark Noble in stoppage-time to rescue the three points.
"We have to work better defensively, no doubt. In the first half, we were too easy to play through," he affirmed following the victory. "We will work on it because there is no respite when you play football. I've spoken about how you can't take rests when you defend."
Solskjaer added: "We dropped into a back six [for the goal] and there were too many spaces. We were too late to charge the ball. We've already sorted that and spoke about that at half-time."
The 48-year-old changed his entire starting XI from Sunday for the third-round clash at Old Trafford, watched by more than 70,000 fans.
With his fringe players not cutting it, Solskjaer hopes those who were making their first starts of the season (eight players) will be ready for other cup competitions.
"We've got to the semi-finals the last two years and it's a competition we've got tradition for to give players minutes because we need to think about the bigger picture," he said.
"Today, we made that decision and some of them will definitely come out stronger for it because they've now got 90 minutes under the belt and are ready for the league and the Champions League, and the FA Cup when that starts."