Manchester United midfielder Casemiro is at a strange moment in his career at present, facing some uncertainty. Right now his successful career is subject of a documentary in Brazil, set to be released on streaming channels in the country on June 15. And yet, with the Copa America kicking off the same weekend, Casemiro finds himself left out of the Brazil squad, following a tough season for Manchester United. Casemiro’s future at Old Trafford is on shaky ground. Manchester United proved able to beat Manchester City without him in the FA Cup Final, and the club are claimed to be looking to cash…