Watford's penalty against Chelsea was one of four examples of VAR incorrectly overruling on field decisions, according to Premier League referees chief Mike Riley.

Riley described the penalty as one of four instances of the "worst possible outcome" of the video assistant referee system in the two weeks before the international break.

The other instances in question occured in games between Everton and Brighton on October 26, Norwich and Manchester United on October 27 and Arsenal and Crystal Palace, also on October 27.

At a meeting of the 20 top-flight clubs, Riley said that on those occasions, VAR had overruled perfectly good decisions by the on-field officials.

Riley also said VAR still needed some improvements, but that he was still "excited" by how he feels it can benefit the Premier League.

"We still have a long way to go," he said.

"We can get better consistency in decision-making from VAR, we can improve the timing so we have minimum interference and if we achieve those - which we will over time - then what we will end up with is better quality decision-making, better than over 90 per cent, and actually in a way that minimises the impact on the game.

"If you have the opportunity to work in something that has the potential to benefit the game to such an extent, it's a great thing to be part of.

"Go back three years, when we started doing the live trial game, and the view of not just myself but all the people involved is we are involved in one of the most exciting things that will happen in football in our lifetime.

"And actually the way you come out with a really good thing that benefits Premier League football throughout, is in that process you engage with everyone."