“The world experience is going very well and Portugal is leading the programme,” Elleray was quoted by the FPF as saying after a technical session with top-flight referees at its headquarters in Oeiras, near Lisbon. “It’s made a lot of progress in this first half of the season.”

Elleray, an English former football referee who has been technical director of the International Football Association Board (IFAB) since May 2016, was taken on by the FPF as a consultant at the end of last year, in a bid to end controversy over the use of video assistant referees (VARs) in first-division games in Portugal.

Elleray monitored Saturday’s and Sunday’s first-division games in Portugal from the video assistant referee operations room, and praised the “technology and the professionals”, who he said acted in “very efficient” fashion.

“I’m in Portugal to try to help the referees to improve what they’re doing,” he went on. “They’re already at a good level, but it is always important to continue to progress and refine [one’s] technique.

“We want to improve the time reviewing moves, so that they have less impact on the game,” he added.