Of course I hope that Serena will win the match.
But she's just gone out to play, we all don't know her condition except herself.
So, I would say, Nastya will win the match.
But Serena also has chance to defeat Nastya, she is not like her sister Venus (Too many UEs...), and her strength will make big trouble for Nastya.
Whatever, do your best Serena, the result is not that important.You need to go back to the top match after match.