Until half-time, both of them are still not able to score any goals. It is quite silly for Arsenal that still cannot give hard attacks to Porto.
Arsenal seems quite difficult to attack Porto. For some reason, this time, Porto was quite strong in their back line, so it wasn't easy for Arsenal to attack. hmmm, will this be a draw match if it continues like this?

So does what happened to Barcelona. I  also  think that Barcelona should win this match. Napoli strategy was still quite confusing and they are now not at a good condition after getting again new coach for them. On the other hand, Xavi should be able to take advantage of this moment to put more pressure on Napoli. And the thing is, Barcelona has it, yes they have those chances. but unfortunately it's still not optimal.