Depends how her 'first strike' lands. As what I know of Na is a very inconsistent player. She needs a very good day to beat an average Vika. Plus she's not mentally stable.
I just say that Na's improved her serves (not her match vs Shu in CO and 2nd set vs Maria in CO, though. ). Vika won't be able to attack them as easy as their last two meetings (3-set matches). Also, Carlos is teaching Na to take the balls earlier to take the time away from her opponents. Hopefully Na will play like her 2012 CO R2 match.
Asian-GOAT-Na Li: 11" FO & 14" AO champion + 11" & 13" AO runner-up + #2 Little-Jie(06" AO & Wim) + Pusher-Shu(13" Wim & 14" FO & WD#1) + Sucky Baby Golden Flowers.