Unai Emery raged at the video assistant referee for failing to flag Elliot Anderson’s dangerous first-half tackle on Ollie Watkins in defeat at Nottingham Forest and claimed the England striker was fortunate to avoid a broken ankle. Villa’s manager said the Portuguese VAR, Tiago Martins, made a “huge mistake” by not alerting the referee, João Pinheiro, to the incident.

Forest prevailed 1-0 in the Europa League first leg at the City Ground courtesy of a 71st-minute Chris Wood penalty, awarded after a VAR review ruled the ball was in play when Lucas Digne handled Omari Hutchinson’s cross inside the box, but Villa were left incandescent about Anderson’s challenge. The referee waved play on when Anderson caught Watkins on his ankle before claiming the ball and the VAR did not intervene. Emery admitted he did not realise the seriousness of the incident until reviewing footage of the tackle after the match.

“It is a huge mistake, a huge mistake, because Ollie Watkins was close to breaking his ankle,” said the Villa manager. “It is the VAR’s responsibility and he must give us an explanation about it because it’s crazy watching this action. Of course, the referee can’t watch it like me. I watched the action of Anderson with Watkins … one action like that can break his ankle.

“I’m working for 20 years as a coach and sometimes they make mistakes, [there are] always tight decisions, without VAR it was more difficult … I am 100% with VAR but we must manage VAR good and in the right way. One action like that doesn’t make sense. It is so, so clear. Where is the doubt? The risk is to the players. Where is VAR?” Emery said, looking around the room. “Wow, crazy.”

Asked if he had spoken to Digne about the decisive penalty, Emery added: “Not yet … and of course tomorrow we will meet and speak about everything we felt today, maybe as well [I will talk] with him. Lucas is a fantastic professional, a fantastic guy. His commitment here, working always 100% is really fantastic. Sure, if he did one action like that, OK, it’s part of football.”

Vítor Pereira praised Forest and vowed his side will attack the second leg at Villa Park next Thursday. “We are at half-time,” he said. “We know that when we play again we will face another tough game. One thing I am sure: we will go there to compete again, not to defend but to win the game. This is the spirit of this team, a special team and it is a privilege to be the manager because they have the character, personality and quality. To have four managers in a season is not easy.”