Not an ounce of certainty. 

Whether we go with Marterer or Kwon we have to expect anything and everything with these two..

Marterer is having a disastrous season, I'm not going to tell you otherwise, he quickly finds himself in difficulty when his serve doesn't make enough difference. A lack of confidence, sensations and simply victories. Playing at home will help, this little extra bit of motivation could fill these little gaps. Especially since it's Kwon facing him, not a scary player and surely one of the best draws in R1. The Korean is always injured, he plays little and we can never predict his level perfectly. I just know that dirt is his worst surface, he doesn't like playing on it, we can't give him the advantage of the surface. In the game he always had small problems on the return, if Marterer serves well and gains confidence he could quickly regain his tennis, to see if we take the risk or not.