I wonder - under Poch the players were exhausted, having to "dominate" and when not in possession needing to enforce a high press.
Under Mourinho, you get to sit back - you have to concentrate mentally, but surely it is significantly less punishing physically.
Perhaps that means Lucas can be "released" at the right time, full of beans and ready to show exactly what he can do.
He was pretty terrible under Mourinho up until two games ago. I think he just has had a decent run of form more than figuring anything out. Even in these good games you see a lot of the old Moura starting to creep in and cause trouble.