Video assistant referees, or VAR, will be used in the Premier League for the first time this season.

Here, PA looks at some of the key issues around the technology ahead of its introduction at Anfield tonight.

What decisions does VAR assist with?

There are a number of ways players can be penalised following the introduction of VAR: yellow cards will be issued for excessive use of the VAR signal towards officials, entering the RRA, interfering with VAR communications and for dissent following a decision.

Likewise, managers and coaches would face the same Football Association disciplinary measures as they do now when criticising officials if they question decisions made by the VAR.