A behind-the-scenes look at the Virtual Assistant Referee in action

The Major League Soccer (MLS) recently created history after joining forces with the United Soccer League (USL) to introduce virtual assistant officiating. We take a behind-the-scenes look at the new innovation.

For the very first time in the game, a number of professional matches took place with the use of the Virtual Assistant Referee (VAR) program.

The VAR, which is by all intents and purposes a video replay system, had been tried out before in leagues such as the NFL and MLB.

However, after the green light from the International Football Association Board, the USL introduced six video referee trials, including in a contest between New York Red Bulls II and Louisville II in August.

During the encounter, referee Hilario Grajeda used the VAR to decide whether a foul in the second half had taken place inside or outside the area, with the official using an iPad on the sidelines to clarify his original call.

"We looked at the two best angles that we had, one that gave us contact and also the RA view to camera from the touchline to determine clearly that the foul had taken place inside," said VAR Allen Chapman.

Meanwhile, the referee in question, Hilario Grajeda, was delighted with how the process had worked: "It was fantastic, we had every angle I needed and it was clear that the foul had taken place inside."

And after the match, Paul Rejer from the Professional Referee Organisation declared the experiment "a success". There was one decision in the game that was changed and it was the correct decision

"I'm delighted, we have created history in the last two weeks and this is a really good situation for the referees as everything can be checked.

"And if they want to instigate a review, they can, and the referees will obviously welcome it as no referee wants to make a bad decision, believe me."

Watch the above video to get a behind-the-scenes look at the VAR in action...