Yeah I know, chances of stumbling upon a viable fix to some of our issues in a game against Copenhagen are very slim. I don't even remember them crossing the halfway line in pressing, that's how little they fancied their chances. So take the following stuff with a grain of salt.
But this 3-2-4-1 in possession we saw especially in the first half, with Porro staying back instead of one of the double pivot dropping between CBs like usual, looked more promising to me. Something like, with adequate changes to today's XI obviously:
Porro-Romero-VdV
Bentancur-Sarr
Johnson-Simons-Odobert-Udogie
RKM
Pros
Puts our -arguably- two best passers in Porro and Romero in a position where they can have the whole pitch in front of them, seeing those forward passes better
Best short term fix I can come up with to the glaring hole on the left, with Udogie playing as a wingback
Could be more conducive to winning the ball in high areas with 5 players up front
Save the best for last: Spares us from the Palhinha-Bentancur double pivot
Cons
Would probably reduce Porro's attacking firepower quite a bit, so not sure if he would buy into this
Heavily dependent on Udogie being healthy and in form, since I don't see Spence being able to make this work
Doesn't really address the issue of lack of a #10, but then I don't know if it's even possible at the moment