The Serb hates losing, but the blow of Sunday's loss was softened by his feelings for Jakub Mensik.
The Czech says he was about to pull out an hour before his first match, but got a break when the tournament referee was not available.
The American says he would have been better off guessing against Mensik's serve.
It takes a lot to impress 24-time Grand Slam champion Novak Djokovic, but this does.
The two-time major champion has long been a mentor to Rublev.
The Togliatty, Russia native announced her switch on social media.
The American converted his seventh match piont against Matteo Berrettini to win in Miami.