MLS and the Professional Referee Organization will continue video assistant referee testing throughout preseason, the league confirmed Monday.
In compliance with the International Football Association Board, the league will use live, in-game tests of the system in an additional 28 preseason matches involving 15 MLS teams this month. MLS then plans to conduct offline VAR testing in regular season matches at all 22 league venues, in hopes of fully implementing the system following the All-Star game Aug. 2.
"These additional tests during preseason, as well as the offline tests during the beginning of the MLS regular season, will enable us to refine the experiment protocols and procedures prior to implementation in league matches," said MLS executive vice president of competition and player relations Todd Durbin in a news release.
VAR is designed to help referees reduce clear errors in four game-changing situations: goals, penalty decisions, straight red cards and cases of mistaken identity.
According to the news release, "The continued testing will focus on ensuring that communication between the referee and the Video Assistant Referee is clear, precise, and efficient, with the aim of reducing avoidable delays to create minimum interference with maximum benefit."
VAR, which was tested in the second-tier USL last season, was used in a match involving MLS teams for the first time Friday, when the system confirmed a penalty decision in the 88th minute of a match between Real Salt Lake and the San Jose Earthquakes.
The IFAB plans to make a final decision about the VAR experiment in 2018 or 2019.