I think Al is the key to this series. He has a HUGE mismatch advantage against Lopez, because while he can guard Lopez out on the perimeter, the same cannot be said about Lopez, who will really struggle to stay with Al.
I think that's why there's a strong possibility that you see us go back to Al at the 5 and probably (gulp) one of Morris or Semi starting at the 4, maybe even a Hayward. I'm a little conflicted about that. While I think that gives us a much better mismatch opportunity to exploit, I'm not sure if it's worth it, as Baynes is a major component of our staunch defense.
That said, I could also see us rolling with the same starters of Kyrie, Brown, Tatum, Al, and Baynes, as Al has done a remarkable job at making thins difficult for Giannis in the past by playing off of him and forcing him to become a jump shooter. And while you lose the Lopez mismatch, Baynes can at least stretch the floor still and draw Lopez out of the paint, and he's probably capable of staying with Lopez out on the perimeter, as well, while also having the size to guard him down low.
Will be interesting to see what route Brad chooses for the starters.