The midfielder was named the Football League's Young Player of the Year for his performances for Leeds last season and he was also named in the England Under-19 squad that will face Mexico next month.
However, Cook has suffered a setback during training with the young Three Lions and has pulled out of the squad due to a minor injury.
The midfielder will be hoping to return to full fitness as soon as possible in order to return to the national team set-up.
Cook made 47 appearances in all competitions for the Whites during the 2015/16 season scoring twice.
He has made nine appearances for the England Under-19s.