Maguire's disastrous start to the season continued when he received a second yellow card just 30 minutes into the Nations League clash at Wembley on Wednesday.
The centre-half twice lunged into tackles late, and referee Jesús Gil Manzano was left with no choice other than to give him his marching orders.
After Maguire's sending-off against Denmark, United legend Neville put the boot into the defender.
"That sums up his last 4-6 weeks," the ex-Red Devils right-back told Sky Sports. "Terrible time for him. I thought he was lucky with the first challenge. That was in between a yellow and a red.
"It's scruffy play from him. The touch is really slack, and then the follow-through..."