Minor clarification... last time Ring and Hererra played together, Ring was the DMid shielding the back line with Hererra playing box to box. That's how he got 1G/1A in the game. Probably stay with that arrangement.
Here's a novel idea.... if Pirlo can't go and has to sub out, what about making Lewis the defacto Poor-man's Silva? I'm pretty sure in the u20 tuneup games I saw him play in, he was pulling Some strings from the middle and arcing to either corner to make the centering cross. Let him pick up the ball in a withdrawn position and with the movement our front line usually makes with Villa swinging left, it could open up a lane for Lewis to race straight at goal with the CB shadowing Villa. Even if he doesn't play a lick of D, I'd take his speed and dribbling in the middle over TMac any day of the week.