Most Goals: Coutinho
Most Assists: Kevin de Bruyne
Most Saves:
this might as well be a wild guess, so I'll say the Uruguayan keeper whatever his name is.
GK - De Gea (Spain will probably concede few but go out on penalties)
DF - Glik (Poland)
DF - Godin (Uruguay)
DF - Sigurðsson (Iceland)
DF - Boateng (Germany)
MF - Cueva (Peru)
MF - De Bruyne (Belgium)
MF - Paulinho (Brazil)
FW - Ronaldo (Portugal)
FW - Griezmann (France)
FW - Coutinho (Brazil)