World No. 4 Karolina Pliskova is already hard at work with her off-season training in hopes of a big 2018. Send her a 🏆 if you think she’ll rack up some titles next season! (📸: @karolinapliskova) #usopen #karolinapliskova #pliskova #tennistraining #wta #tennis #protennis #instatennis #instasports