Does he have handlangers who mix and bring cement, fetch bricks, and assist with line? If the lay is straight, no cuts, uncomplicated, double, then around 750 stock bricks a day for an experienced professional bricklayer.
About 500 bricks properly layed ie: not the rubbish jobs you get these days because everything is going to be plastered over. So about 500 commons. That is with a hod carrier and mortar supplied.
Loads of people these day who can throw one brick/block on top of another, very few skilled brick layers around.