#4 All promise, no effectiveness
There were plenty of good individual performances across the pitch, but Manchester United weren't able to stitch them all together. Daniel James perhaps personified that as he started off playing upfront in an unfamiliar position and was fairly invisible for the early phases of the game. His move to the wing saw him get more involved and start to make use of his pace and trickery to try and take on players, but little movement around him let him down.
Similarly, Angel Gomes on the other wing showed signs of life in spurts but quickly found that his team-mates weren't on the same wavelength as him. By the time Marcus Rashford came onto the pitch and started to impact play for Manchester United, it was already too late.
The attacking moves that Alkmaar made were much more coherent with Idrissi and Boadu linking up well. Even the 19-year-old Japanese full-back Sugawara had a few good moments against Brandon Wilson, especially when he combined with Stengs on the flank, but they were unfortunate not to find the back of the net.