Chelsea manager Frank Lampard has said Harry Maguire should not have been on the pitch when he scored his side's second goal in a 2-0 Premier League win on Monday after the Manchester United defender escaped a red card for kicking Michy Batshuayi.
The Video Assistant Referee (VAR) system was in the spotlight once again after Maguire kicked Batshuayi in the groin area in the first half at Stamford Bridge.
"Maguire should have been sent off," Lampard told British media. "That's clear, and that obviously changes the game."
United captain Maguire, who escaped sanction for the incident, went on to score a thumping header in the 66th minute to seal the win.
"Decisions like that are crucial," added Lampard. "That's a major part of what VAR was brought in for: a second viewing, different angles. I don't get why they aren't looking at the monitor. It should be used."
VAR also ruled out two Chelsea goals from Kurt Zouma and Olivier Giroud in a frustrating night for Lampard's side, who went a fourth straight league match without victory.
"The Zouma goal should have stood," Lampard added.
"Giroud's goal being ruled out is a bit soul destroying but it's the culmination of a few incidents."