It could go to either Felix or Kluber at this point. They are both deserving. If Felix bombs out tomorrow ... it is likely Kluber's, but Felix would really have to bomb out.
Felix will likely end with more IP, lower BB/9, lower ERA,lower WHIP, lower batting average against, lower ERA-, lower xFIP.
Kluber will have a higher K/9, lower FIP, lower FIP-, more Wins.