Two Major League Soccer reserve teams will be the first to experiment with live Video Assistant Referees (VAR) after receiving approval from world football's top rules committee.
In June, MLS was selected as one of six leagues to test video replay reviews over the next two to three years.
The International Football Association Board (IFAB) have now given permission for the tests to begin, with the first test set for Friday night's USL game between the New York Red Bulls II and Orlando City B at Red Bull Arena.
Under the experiment, an additional referee will sit in a video booth with access to replays from all available cameras. He will then advise the head referee on "game-changing" decisions including goals, penalty decisions, straight red cards and cases of mistaken identity.
The reviews begin less than a week after MLS admitted that the Red Bulls senior team should have been awarded two penalties in Sunday's game at the LA Galaxy.
Red Bull Arena will then host four more VAR experiments in the USL this season after hosting an IFAB workshop last month.
"During the last workshop, we received significant feedback from the participating competition organizers from across the world," IFAB Secretary Lukas Brud said in a statement.
"We believe that these additional tests will enable us to refine the experiment protocols and implementation procedures which are key to the success of the forthcoming trials."